Geological Software (dr Asem Ahmed Hassan).pdf

SedLog: Drawing graphic logs software Prepared by Dr Asem Ahmed Hassan

SedLog is a shareware multi-platform software for creating graphic sediment logs. It provides an intuitive graphical user interface, making it very easy for anyone to use with minimum effort. The graphic sediment logs generated by SedLog can be exported as PDF, SVG (Scalable Vector Graphics), or Joint Photographic Experts Group (JPEG) for use by other drawing applications or for publications. Log data can be imported and exported in CSV (comma separated variables) format. The logs can also be printed to any paper size the user wants. Zoom In, Zoom Out, Fit page, Fit Height and Fit Width facilities are also provided to enable the user to customise the workspace size. Sediment log files generated by SedLog have the *.SLG extension. Template files generated by SedLog have the *.TEM extension. SLG and TEM can be opened and modified only from the SedLog. After installation, you can find sample files in the examples folder of SedLog. This folder is located in the folder you selected to install SedLog. In the case of MS Windows the default folder (unless you selected otherwise during installation) will be C:\Program Files\SedLog\examples\. Files with the *.SLG extension are graphic log files and are generated by SedLog. Files with the *.CSV extension are log data files and can be created and opened by any spreadsheet applications such as Microsoft Excel. The SedLog can be used for research and teaching without charge. The program is available free from www.sedlog.com. If you are intending to us the software for commercial purposes, please seek a license from RHUL by contacting: [email protected]

Departments of Computer Science and Earth Sciences. Royal Holloway, University of London

Reference:

"SedLog: a shareware program for drawing graphic logs and log data manipulation", D. Zervas, G.J.

Nichols, R. Hall, H.R. Smyth, C. Lüthje and F. Murtagh, Computers & Geosciences, 35, 2151­2159, 2009.

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SedLog

Introduction: The graphic sedimentary logs

The graphic sedimentary log is the standard method used by geologists to present data from successions of rocks. These successions may be from cliffs or quarry faces where rocks are exposed, or in core drilled through layers of rocks in the subsurface. From each bed data are recorded and summarised in a largely diagrammatic format to create a representation of the strata in a form that can easily be related to the bed characteristics. The thickness of the bed is measured, the lithology determined (sandstone, mudstone, limestone, etc.), the presence of any structures, such as ripple marks, noted and other features such as the fossil content recorded. This information is presented on the graphic log using a vertical scale for the bed thickness, patterns to represent different lithologies (‘dots’ for sandstone, ‘bricks’ for limestone and so on) and symbols to illustrate structures and fossils. Other data that may be recorded and indicated on the log may include other features such as colour, the locations where rock samples have been taken or other specific information from different points in the succession. Logs may be used to compare strata between different areas and data may be extracted from the log to analyse trends in bed thickness, distribution of lithologies or 2

other features. They can be drawn in the field as summary sketch logs, or on log sheets that contain all the data from the succession and later drawn up in a neater form for reports or publications. Although they are most commonly used by sedimentologists, they are widely used by geologists working in many other fields, such as volcanology, igneous petrology and palaeontology. Logs were originally hand-drawn, but with the advent of graphical drawing packages it is now usual for logs presented in commercial reports and scientific publications to be images generated by computer graphics. Whilst these can provide a satisfactory representation of the information, the actual data is not recorded in any form that can be analysed in any numerical way. For example, any statistical analysis of trends in bed thickness or the distribution of different lithologies would require returning to the original data set to access the numerical information. A further drawback of logs presented only as pictures is that if substantial changes need to be made, such as using a different vertical scale, the log may need to be almost completely re-drawn. Computer-drawn logs, therefore, offer little advantage over their hand-drawn predecessors—they are just neater. Some software packages are available, e.g. WinLoG (http://www.gaea.ca) or LogPlot (http://www.rockware.com) that can use a database of information to generate sedimentary logs, either as stand-alone utilities or as parts of larger, integrated suites. Not all are well-suited to the needs of all geologists: in some cases, the data input is not straightforward, as parameters may need to be defined at the outset, and output may not have the desired flexibility. The greatest obstacle to the widespread use of many of these packages is, however, their cost: even if some of the packages can satisfy many of the requirements for input and presentation of sedimentological data, they are not readily available and affordable for use by students and others without the resources to purchase the software licenses.

SedLog characteristics

1. A user friendly multi-platform software written in Java for creating graphic sedimentary logs. 2. The application as complete as possible without any need for other software. 3. SedLog can draw logs by dragging and dropping, and also has a full range of patterns and many other attributes built in. 4. The logs can be p Zoom In, Zoom Out, Fit page, Fit Height and Fit Width facilities are also provided to enable the user to customise the workspace size. 5. The graphic sedimentary logs produced by SedLog can be printed directly from the screen or exported as vector images to other graphics packages. 6. All data can also be output to spreadsheets (CSV file format) for statistical analysis or export into other packages that handle sedimentolo-gical or stratigraphic information. 7. Data in spreadsheet format can be imported into SedLog and can be used as the basis for drawing a graphic log. 3

SedLog User Interface

SedLog User Interface 1.Title bar:

2.Menu bar

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3.Toolbar

4. Plot window (workplace)

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Menu bar: 1.File

2.Edit

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3. View

4. Statistics

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5. Tools

6. Help

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Data input in SedLog The data set for a succession of rocks is built up on a bed-by-bed basis. After creating a new file, information about the first bed (the lowest) is entered via an input menu (Figure 1). The only data required for every bed is its thickness, and as much or as little other information as is required can be entered initially: all data pertaining to a bed can be edited subsequently.

Create a log from scratch You can create a log from scratch by using a window (see Figure 1) to enter the log data after selecting the Add Bed option from the Edit menu; alternatively click Add Bed

on the toolbar. The Edit menu can also invoked by clicking the right mouse button. The dialog box enables the user to specify a bed's properties. The only data required for every bed is its thickness, and as much or as little other information as is required can be entered initially: all data pertaining to a bed can be edited subsequently. On the input window a series of drop-down menus provide options for recording information about the bed. (a) Lithology, including the option of recording the proportions of up to three different lithologies for a single bed; by default the first lithology entered is 100%; a set of patterns are provided for the most common lithologies and are displayed in the dropdown menu. (b) Type of basal contact, gradational, sharp or erosional. (c) The grain size at the base and at the top of the bed (the basal grain size is assumed for the whole bed unless a size is entered for the top): the menu provides name descriptors such as 'coarse sand', 'medium-fine sand' etc, but the program also records the equivalent phi scale value. On the graphic log these are displayed using a scale with increasing grain size towards the right. (d) Sedimentary structures 'within the bed': a variety of symbols is available to represent the commonest structures (trough cross bedding, symmetrical ripples and so on) and can be displayed as single symbols or as tiled symbols filling the grain size 'curve'. The lithology patterns can also be inserted into the grain size column to create the merged lithology/grain-size arrangement which is also commonly used. (e) Symbols 'beside the bed': sedimentary structures, fossils and bioturbation features can all be displayed, either singly or in combinations in a column. (f) A 'Notes' column allows for text of numerical information to be entered 9

Figure 1. Adding a new bed (Data input menu, main interface in SedLog for entering data bed-by-bed) Once a bed has been created it can be modified using the properties window (Figure 2) after selecting the Bed Properties option from the Edit menu; alternatively click Bed Properties

on the toolbar or double click the left mouse button on the selected bed.

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Figure 2. Change or view a bed's properties

*Beds can be deleted, copied or inserted into specific parts of the log table using the menu options. To delete a selected bed click Delete Bed in the Edit menu; alternatively click Delete Bed

on the toolbar.

*To insert a new bed into a specific part of the log click Insert Bed Under Selected Bed in the Edit menu; alternatively click Insert Bed Under Selected Bed on the toolbar.

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Create a log by importing a CSV file

SedLog takes as input data files containing the sediment data in CSV format. CSV (or comma-separated values; also known as a comma-separated list or comma-separated variables) file format is a file type that stores tabular data. It is a text file data format that has fields/columns separated by the comma character and records/rows separated by newlines. Fields that contain a special character (comma, newline, or double quote), must be enclosed in double quotes. Bellow is a sample CSV file opened by a text editor: "THICKNESS (CM)","BASE BOUNDARY","LITHOLOGY","LITHOLOGY %","GRAIN SIZE BASE","GRAIN SIZE TOP","SYMBOLS IN BED" 100,"","Limestone",100,"vf","vf","Intense bioturbation" 45,"Sharp","Shale",100,"clay","clay","" 45,"Erosion","Conglomerate",100,"pebble","granule","Cephalopods" 135,"Gradational","Sandstone",100,"vc","m","Trough cross bedding" 65,"","Sandstone",100,"m","m","Planar cross bedding" 50,"","Sandstone",100,"f","f","Current ripple cross-lamination" 60,"Sharp","Siltstone",100,"silt","silt","" 35,"","Coal",100,"","","" 65,"Sharp","Siltstone",60,"clay/silt","clay/silt","Moderate bioturbation"

- CSV files can be created or opened by any spreadsheet application such as Microsoft Excel. When you are creating an input data file for SedLog using a spreadsheet application such as MS Excel make sure to save it in CSV format using the Save As option not the default one. -The CSV format does not store information such as column width, colour, etc, so when you will try to save a spreadsheet to CSV format the spreadsheet application will warn you that you will loose some information saving it in CSV format. Don’t worry about it, proceed and save it as CSV. Below (see Figure 1) you can see a screenshot of a CSV file opened in Microsoft Excel:

Figure 1. A CSV file opened in MS Excel 12

To import a CSV file, choose from the File menu import a log from a CSV file. A dialog box (see Figure 2) will appear. If the CSV file you want to import has been generated by SedLog choose Automatic Importing. Automatic importing will import all the columns in the CSV file. If the CSV file was created by another application such MS Excel or you want to select which column to import from the CSV file choose Custom Importing. Using Custom Importing one can select which columns are to be selected for import and these columns can be assigned then to the corresponding log columns.

Figure 2. Importing a CSV file to SedLog In the Imported Columns list box on the left of the dialog box are displayed the headers of the columns of the imported CSV. Click on the Imported Columns list box to select which column from the CSV file you want to import. Then use the Assign Imported Column To combo box on the top right of the dialog box to assign the imported column to the corresponding SedLog's log column. Only the columns present at the Assigned Columns box at the bottom right of the dialog box are going to be imported.

Display the log key

Each lithology pattern and symbol used in the construction of a log is stored in a separate file containing the matches of names and patterns/symbols used in that log. In the View menu, click Log Key; alternatively click Log Key on the toolbar. A window will appear (see figure bellow) displaying the log key. This can either be printed as a simple key, or exported in PDF or JPEG for use by other drawing applications or for publications. 13

Customise the graphic log

Log Key

To change the column width, position the mouse pointer on the edge of the column you want to resize. The mouse pointer will change to a two way arrow. Hold down the left mouse key and drag the mouse to resize the column. Using the preferences window (see figure bellow) the user can change the layout and format of the log table to suit particular needs. The preferences window can be invoked by selecting Preferences in the Tools menu; alternatively click Preferences on the toolbar. Alternative layouts can be used, using all or some of these columns, or using some of the following additional columns. (a) Bioturbation (the disturbance of sedimentary deposits by living organisms): this column may be used to display symbols for different types of ichnofauna plus a value to indicate the intensity of the bioturbation. (b) Facies (a body of rock with specified characteristics or a distinctive rock unit that forms under certain conditions of sedimentation, reflecting a particular process or 14

environment): A useful way of the showing the facies is to use a narrow column for each facies and filling in the column adjacent to the appropriate beds. This format of representing facies information can provide a quick, visual impression of the distribution of facies within a succession, and if the order of the columns is arranged appropriately, for example with the shallowest representation of depositional environment on the left and the deepest on the right, then shallowing or deepening trends can be recognised. (c) Palaeocurrent data is recorded bed-by-bed with multiple entries for a single bed possible: SedLog stores the data numerically, but it can be displayed on the graphic log either as numbers of as arrows with appropriate orientations. (d) Columns for stratigraphic information: 'Age' and 'Formation' columns are intended to be placed on the left side of the log, with boundaries between stratigraphic units entered at the appropriate bed and names displayed with text aligned vertically. (e) Three (Other 1,2, 3) further user-defined columns are available for entering either text or numerical data. These may be used to record features such as colour, the positions of samples or data that result from geochemical or other analyses. Any of the columns can be renamed via a layout window (see figure bellow) and this window can also be used to modify a number of other aspects of the appearance of the graphic log. Several different scales are available, from 1:10 to 1:1000; there are also options on the intervals for display of the numbers on the scale and the scale can either measure form bottom to top for outcrop or downward for depth in borehole core. The size of the symbols, the magnification of the lithology patterns and the font sizes can be adjusted to suit different log scales. The order of the positions of the columns from left to right can be changed as required, and the name of the column customised. The default title at the top of the grain size scale is a dual clastic and carbonate scale, but either can be used on its own. The title of the log is also inserted via this window. An important consideration in the design of SedLog has been the desire to allow the user as much flexibility as possible in the appearance of the output, although there are some limitations: for example, 1.The total number of columns available is fixed and 2.Symbols can only be inserted into some columns. The width of columns can be modified on-screen by click-and-drag of the column boundaries. Once a layout has been created it can be saved as a template for multiple data sets.

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Preferences

How to create new lithologies/symbols

SedLog allows the user to import new lithologies and symbols in SVG/SVGZ format (see Add new litholgies/symbols to SedLog). SVG (Scalable Vector Graphics) is an XML specification and file format for describing two-dimensional vector graphics, both static and animated. It is an open standard created by the World Wide Web Consortium's SVG Working Group. SVGZ are compessed SVG files. You can create your own SVG/SVGZ files by using a vector graphics software such as Inkscape, CorelDraw, Adobe Illustrator, Adobe Photoshop etc. Inkscape is a free and open source vector graphics editor application. Its stated goal is to become a powerful graphic tool while being fully compliant with the XML, SVG and CSS standards. Inkscape is primarily developed for Linux, but it is cross-platform and runs on Mac OS X (under X11), other Unix-like operating systems, and Microsoft Windows. Inkscape has multilingual support, particularly for complex scripts, something currently lacking in most commercial vector graphics applications. You can download Inkscape from: www.inkscape.org. 16

SVG/SVGZ format is a vector graphics image format as opposed to a raster graphics image. Computers can store images either: a) as a raster graphics image or bitmap, or b) as a vector graphics image. Bitmaps are matrices of pixels and appear jagged when rescaled or printed. Vector graphics use geometrical primitives such as points, lines, curves, and polygons to represent images and continue to look the same when rescaled or printed. Examples of raster graphics image or bitmap file formats are: JPEG, GIF, BMP and PNG. Examples of vector graphics image formats are: SVG/SVGZ, PDF etc. You can use also Inkscape to convert patterns or symbols saved in other formats such as AI, PDF, JPEG, GIF, BMP, PNG, etc to SVG or SVGZ. If the file you want to convert is a bitmap (raster image) then first you have to use Inkscape to converted it to vector format before you save it as SVG. To do this first open the bitmap using Inkscape. Then select the loaded bitmap by clicking the Select All option from the Edit menu. From the Path menu select Trace Bitmap (see figure 1 below). A dialog box with various options will appear (see figure 2 below). Select the Colors option (if you not select this option the resulting image will be black and white) and press OK. The vector version of the image will be created on top of the original bitmap image. Select the vector version and move it a little to reveal the original (bitmap). Select the bitmap and remove it. Save the image as SVG. You may need to play around with various options until you get it right.

Figure 1. Inkscape

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Figure 2. Trace Bitmap NOTE: Make sure that the bitmap you provide is not to small. The bigger the bitmap the better the results of the tracing will be. To rescale or modify a bitmap you can use GIMP (GNU Image Manipulation Program) a free cross-platform software for editing and creating raster images. You can download GIMP from: www.gimp.org For more information how to use Inkscape, consult the Inkscape manual.

Add new lithologies/symbols

SedLog allows the user to import new or edit existing lithologies and symbols in SVG/SVGZ format. For details how to create SVG files for patterns and symbols see (How to create new lithologies/symbol) After you created your pattern or symbol in SVG/SVGZ format you need to import it to SedLog. Go to Tools and select Lithologies/Symbols A window will open which displays the lithologies and symbols (see figure 1). Select to which group you want to add the new lithology or symbol using the Group combo box. There are two Group combo boxes, one for the lithologies and one for the symbols. After selecting the group to which you want to add the lithology or the symbol, click on the Import button (there are two Import buttons one for lithologies and one for the symbols). A new window will open 18

(see figure 2). Click the Add File button. An Open file dialog will open. Select the file you want to import and click OK. You can select more that one SVG/SVGZ file(s) by holding down the <SHIFT> or key and clicking on the files you want to select. The file(s) you selected to import, will appear in the SVG files list box (see figure 2). You can add more or remove files from the list box. At the Type text box (see figure 2) you can change the lithology type name of the selected file in the list box. The default type name is the filename minus the extension. After you enter a new type name click the Edit button (see figure 2) to modify the lithology type to the new one you entered. Select OK. To rename, remove or add new groups click the Edit Groups button (the are two Edit Group buttons, one for the lithologies and one for the symbols) on the Lithologies/Symbols dialog box (see figure 1). A dialog box (see figure 3) will appear with options for renaming, adding or removing a group.

Figure 1. Import, edit, delete Lithologies and Symbols or edit groups

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Figure 2. Add new lithologies to a group

Figure 3. Edit groups 20

Templates

Template files enable a user to create the layout and format of a log table once and reuse it subsequently. SedLog template files have the *.TEM extension. TEM files are native to the application and can be loaded and modified only by SedLog. To create a template go to the File menu and click Save Template (Figure 4). To load a template go to File and click Open Template. After you loaded the template the current layout will change to that of the template. If you load a file the layout will change to the new file's layout. So you first load a file and then you load a template to change the current layout.

Figure 4. Create a template and Save a template

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Data export into other programs All the information that is entered via the input menu can be exported in a CSV format file which can be opened in a spreadsheet program. The data for each bed are presented as a row, with columns for each of the parameters entered for that bed (grain size, lithology, symbols and so on). Analysis of the data can then be carried out to determine patterns and trends in be bed thickness, grain size, facies, bioturbation intensity, etc. Palaeocurrent data are stored as comma-delimited strings that can be exported into rose diagram plotting programs. Data exported from SedLog can be imported into any program that uses ASCII format. The graphic sediment logs generated by SedLog can be exported as PDF, SVG, or JPEG for use by other drawing applications or for publications. To export a log as PDF, CSV, SVG or JPEG select Export from the File menu. A dialog box (see figure 5) will appear to save the log in PDF, CSV, SVG or JPEG format. The user can also print the log using the file menu- Print option, alternatively click on the Toolbar.

Figure 5. Create a template and Save a template Data Export 22

Surfer-Surface Mapping System

Introduction:

(Golden Software www.goldensoftware.com)

Surfer is a powerful contouring, gridding, and surface mapping package for scientists, engineers, educators, or anyone who needs to generate maps quickly and easily. Producing publication quality maps has never been quicker or easier. Maps can be displayed and enhanced in Surfer. Adding multiple map layers, customizing the map display, and annotating with text can create publication quality maps. Virtually all aspects of your maps can be customized to produce exactly the presentation you want. Surfer is a grid-based mapping program that interpolates irregularly spaced XYZ data into a regularly spaced grid. Grids may also be imported from other sources, such as the United States Geological Survey (USGS). The grid is used to produce different types of maps including contour, vector, image, shaded relief, 3D surface, and 3D wireframe maps. Many gridding and mapping options are available allowing you to produce the map that best represents your data. An extensive suite of gridding methods is available in Surfer. The variety of available methods provides different interpretations of your data, and allows you to choose the most appropriate method for your needs. In addition, data metrics allow you to gather information about your gridded data. Surface area, projected planar area, and volumetric calculations can be performed quickly in Surfer. Cross-sectional profiles can also be computed and exported.

Map Types

Several different map types can be created, modified, and displayed with Surfer. These map types include contour, base, post, classed post, image, shaded relief, 1-grid vector, 2-grid vector, 3D surface, and 3D wireframe maps. 1. Contour Maps A contour map is a two-dimensional representation of three-dimensional data. Contours define lines of equal Z values across the map extents. The shape of the surface is shown by the contour lines. Contour maps can display the contour lines; they can also display colors and patterns between the contour lines.

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This is a contour map consisting of contour lines representing elevation. 2. Base Map Base maps display boundaries on a map. Boundaries can include roads, buildings, streams, lakes, etc. Base maps can be produced from several file formats. Empty Base Maps allow you to create a base map with no objects. Objects can be manually added and removed as needed.

This is a base map of Michigan with county polygons. One of the individual polygons has fill. 3. Post Maps Post maps and classed post maps show data locations on a map. Post symbols and the individual post label positions can be customized.

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The post map layer has black symbols. The classed post map layer has red circles and blue squares. Only a sample of the data set is displayed in the classed post map.

4. Image Maps and Shaded Relief Maps Image maps and shaded relief maps are raster images based on grid files. Image maps assign colors based on Z values from a grid file. Shaded relief maps assign colors based on slope orientation relative to a light source.

The same [.GRD] file (sample file Helens2.GRD) was used to create the image map on the left and the shaded relief map on the right. 5. Vector Maps 1-grid and 2-grid vector maps display direction and magnitude data using individually oriented arrows. For example, at any grid node on the map, the arrow points in the direction of steepest descent ("downhill") and the arrow length is proportional to the slope magnitude. In Surfer, 3

vector maps can be created using the information in one grid file (i.e. a numerically computed gradient) or two different grid files (i.e. each grid giving a component of the vectors).

6. 3D Surfaces Surfaces are color three-dimensional representations of a grid file. The colors, lighting, overlays, and mesh can be altered on a 3D surface.

This is a 3D surface map of the Telluride, Colorado USGS SDTS grid file. 7. Wireframes Wireframes are three-dimensional representations of a grid file. A wireframe is created by connecting Z values along lines of constant X and Y. At each XY intersection (grid node), the height of the wireframe is proportional to the Z value assigned to that node. The number of columns and rows in the grid file determines the number of X and Y lines drawn on the wireframe.

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This is a 3D wireframe map with a custom rotation (47°), tilt (49°), and field of view (112°).

Surfer Flow Chart

This flow chart illustrates the relationship between XYZ data files, grid files, contour maps, and 3D surface maps. This flow chart can be applied to any grid based map types. This example displays only two of the grid based maps (i.e. contour and 3D surface).

This flow chart illustrates the relationship between XYZ data files, grid files, contour maps, and 3D surface maps. This example used the DEMOGRID.DAT sample data file, the DEMOGRID.GRD sample grid file, and the RAINBOW.CLR sample color file to fill the contour and 3D surface map 5

Surfer User Interface

Surfer contains three document window types: the plot document, worksheet document, and grid node editor. Maps are displayed and created in the plot document. The worksheet document displays, edits, transforms, and saves data in a tabular format. The grid node editor displays and edits Z values for the selected grid. The Surfer user interface layout consists of the title bar, menu bar, tabbed windows, toolbars, object manager, and status bar.

This is the Surfer plot window with the Object Manager on the left, the worksheet and grid node editor tabs on the top of the horizontal ruler.

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Surfer Layout The following table summarizes the function of each component of the Surfer layout. Component Name Component Function Title Bar The title bar lists the program name plus the saved Surfer [.SRF] file name (if any). An asterisk after the file name indicates the file has been modified. Menu Bar The menu bar contains the commands used to run Surfer. Tabbed Documents Surfer supports tabbed documents. Multiple plot documents, worksheet documents, and grid node editor documents can be tabbed. Toolbars The toolbars contain Surfer tool buttons, which are shortcuts to menu commands. Move the cursor over each button to display a tool tip describing the command. Toolbars can be customized with the Tools | Customize command. Status Bar The status bar displays information about the current command or activity in Surfer. The status bar is divided into five sections. The sections display basic plot commands and descriptions, the name of the selected object, the pointer map coordinates, the pointer page coordinates, and the dimensions of the selected object.

Object Manager

The status bar also indicates the progress of a procedure, such as gridding. The percent of completion and time remaining will be displayed The Object Manager contains a hierarchical list of all the objects in a Surfer plot document displayed in a tree view. The objects can be selected, added, arranged, and edited. Changes made in the Object Manager are reflected in the plot document, and vice versa. The Object Manager is initially docked at the left side of the window, giving the window a split appearance; however, it can be dragged and placed anywhere on the screen.

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Opening Windows Selecting the File | Open command opens any of the three window types, depending on the type of file selected. The File | New | Plot command creates a new plot window. The File | New | Worksheet command creates a new worksheet window. A.

Open

The File | Open command opens a file into a new window. A Surfer file [.SRF] opens in a plot document, a grid file [.GRD] opens into the grid node editor, and data files open in the worksheet. You can also click on the

button on the toolbar, or press the CTRL + O on

the keyboard to open files. The Open Dialog Use the File | Open command in the plot document, worksheet document, or grid node editor to open the Open dialog.

B. New You can create (1) a new plot document or (2) worksheet with the File | New command. (1) New Plot Document Use the File | New | Plot command, or click the Maps are created in a plot document.

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button to create a new plot document.

(2) New Worksheet Use the File | New | Worksheet command, click the keyboard command to create a new worksheet window.

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button, or use the CTRL + W

Using Surfer The most common application of Surfer is to create a grid-based map from an XYZ data file. The Grid | Data command uses an XYZ data file to produce a grid file. The grid file is then used by most of the Map menu commands to produce maps. Post maps and base maps do not use grid files. The general steps to progress from a XYZ data set to a finished, grid-based map are as follows: 1. Create a XYZ data file. This file can be created in a Surfer worksheet window or outside of Surfer (using an ASCII text editor, for example). 2. Create a grid file [.GRD] from the XYZ data file using the Grid | Data command. 3. To create a map, select the map type from the Map menu and use the grid file from step two. Grid-based maps include contour, image, shaded relief, vector, 3D surface, and 3D wireframe maps. 4. Use File | Save to save the map as a Surfer file [.SRF].

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Lesson 1: Creating XYZ Data Files XYZ data files are files containing at least three columns of data values. The first two columns are the X and Y coordinates for the data points. The third column is the Z value assigned to the XY point. Although it is not required, entering the X coordinate in column A, the Y coordinate in column B, and the Z value in column C is a good idea. Surfer looks for these coordinates in these columns by default. You can customize the default columns for XYZ data with the Data | Assign XYZ Columns worksheet command. Surfer requires the use of decimal degree Latitude (Y) and Longitude (X) values when using Latitude and Longitude values. Latitude and Longitude in Decimal Degrees Latitude and Longitude coordinates are often presented in degrees, minutes, and second, such as 39°25'30" (39 degrees, 25 minutes, 30 seconds). However, Surfer can only plot values in decimal degrees. So, for example, 39°25'30" is referred to as 39.425 in Surfer. Converting from degrees, minutes, and seconds is actually quite easy. There are 60 minutes in one degree and 3600 seconds in one degree. To convert minutes and seconds to decimal degrees, divide minutes by 60, divide seconds by 3600, and then add the results to obtain the decimal equivalent. Conversion Equation: Decimal Degrees = Degrees + (Minutes / 60) + (Seconds / 3600) Example Consider the latitude value 39°25'30". This value needs to be converted to decimal degree in order to use it in Surfer. To convert 39°25'30" to decimal degrees: 1. First, convert minutes (25') and seconds (30") to their degree equivalents and add the results. 25'/60 = 0.4167 30"/3600 = 0.0083 0.4167 + 0.0083 = 0.425 2. Then, add this number to the number of degrees. 39 + 0.425 = 39.425 3. The final result is the decimal degree value. 39°25'30" = 39.425°

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Opening an Existing Data File To look at an example of an XYZ data file, you can open TUTORWS.DAT into a worksheet window: 1. Choose the File | Open command, or click the button to select the XYZ data file to display in the worksheet window 2. Double-click on the SAMPLES folder. In the list of files, click TUTORWS.DAT and then click the Open button to display the file in the worksheet window. 3. Notice that the X coordinate (Easting) is in column A, the Y coordinate (Northing) is in column B, and the Z value (Elevation) is in column C. Although it is not required, the header text (the text in row 1) is helpful in identifying the type of data in the column, and this information is used in dialogs when selecting worksheet columns.

Creating a New Data File The Surfer worksheet can also be used to create a data file. To open a worksheet window and begin entering data: 1. Choose the File | New | Worksheet command, or click the worksheet window is displayed.

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button. A new empty

2. The active cell is selected by clicking on the cell or by using the arrow keys to move between cells. The active cell is indicated by a heavy border and the contents of the active cell are displayed in the active cell edit box. The active cell location box shows the location of the active cell in the worksheet. Letters are the column labels and numbers are the row labels. 3. When a cell is active, enter a value or text, and the information is displayed in both the active cell and the active cell edit box. 4. The BACKSPACE and DELETE keys can be used to edit data as you type. 5. Press the ENTER key and the data are entered into the cell. 6. To preserve the typed data in the active cell, move to a new cell. Move to a new cell by clicking a new cell with the pointer, pressing one of the arrow keys, or pressing ENTER.

Saving the Data File When you have completed entering all of the data:

1. Choose the File | Save command, or click the button. The Save As dialog is displayed if you have not previously saved the data file. 2. In the Save as type list, choose the DAT Data (*.dat) option. 3. Type the name of the file into the File name box. 4. Click the Save button and the Data Export Options dialog opens. 5. Accept the defaults in the Data Export Options dialog by clicking the OK button. The file is saved in the Golden Software Data [.DAT] format with the file name you specified. The name of the data file appears at the top of the worksheet window and on the worksheet tab.

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Lesson 2: Creating a Grid File Grid files are created using the Grid | Data command. The Grid | Data command requires data in three columns, one column containing X data, one column containing Y data, and one column containing Z data. We have included a sample XYZ data file (TUTORWS.DAT) with Surfer for you to see how to produce a grid file. To produce a grid file from TUTORWS.DAT: 1. Create a new plot window with the File | New | Plot command. 2. In the plot window, choose the Grid | Data command. The Open Data dialog is displayed. 3. In the Open Data dialog, click the file TUTORWS.DAT (located in Surfer's SAMPLES folder). The name appears in the File name box below the list of data files. 4. Click the Open button and the Grid Data dialog is displayed. Alternatively, you can double-click the data file name to display the Grid Data dialog. 5. The Grid Data dialog allows you to control the gridding parameters. Take a moment to look over the various options in the dialog. Do not make changes at this time, as the default parameters create an acceptable grid file.

Use the Grid Data dialog to set gridding preferences and create a grid file.      

The Data Columns group is used to specify the columns containing the X and Y coordinates, and the Z values in the data file. The Filter Data button is used to filter your data set. The View Data button is used to see a worksheet preview of your data. The Statistics button is used to open a statistics report for your data. The Gridding Method group is used to specify the interpolation gridding method and advanced options. The Advanced Options button is used to specify advanced settings for the selected Gridding Method. 15

   

The Output Grid File group is used to specify the path and file name for the grid file. The Grid Line Geometry group is used to specify the XY grid limits, grid spacing, and number of grid lines (also referred to as rows and columns) in the grid file. The Grid Report option is used to specify whether to create a statistical report for the data. The Cross Validate button is used to assess the quality of the gridding method.

7. Click the OK button. In the status bar at the bottom of the window, a display indicates the progress of the gridding procedure. By accepting the defaults, the grid file uses the same path and file name as the data file, but the grid file has a [.GRD] extension. 8. By default, a Surfer dialog appears after gridding the data with the full path name of the grid file that was created. Click the OK button in the Surfer dialog. The TutorWS.GRD grid file is created. 9. If Grid Report was checked in the Grid Data dialog, a report is displayed. You can minimize or close this report.

Lesson 3: Creating a Contour Map What are contour maps? A contour map is a plot of three values. The first two dimensions are the X, Y coordinates, and the third (Z) is represented by lines of equal value (the contour lines on the map) across the map extents. The shape of the surface is shown by the contour lines. What are contour maps used for? Contour maps are used for a variety of applications. You can contour any Z value of data. If you had multiple Z values for your X, Y values, you could create multiple contour maps. For example, you could create a contour map for X, Y, Z (elevation) to show the topography of your study area. You could then create a contour map for X, Y, Z (concentration) to show the concentration values across your study area. The Map | New | Contour Map command creates a contour map based on a grid file. To create a contour map of the TUTORWS.GRD file created in the previous lesson: 1. Choose the Map | New | Contour Map command, or click the button in the map toolbar. 2. The Open Grid dialog is displayed. The grid file you created in Lesson 2 (TUTORWS.GRD) is automatically entered in the File name box. If the file does not appear in the File name box, select it from the file list. 3. Click the Open button to create a contour map. 4. The map is created using the default contour map properties. 5. If you want the contour map to fill the window, choose the View | Fit to Window command. You can also use the view menu or view buttons on view toolbar to zoom in, zoom out… etc. the map.

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Map Properties After creating a map, you can change the map properties.   

By selecting the Edit | Properties command when the object is selected, By double-clicking on the object in the plot window or in the Object Manager, Or by right-clicking on an object in the plot window or in the Object Manager and selecting Properties.

Changing Contour Levels After you create a contour map, you can easily modify any of the map features. For example, you might want to change the contour levels displayed on the map. To change the contour levels of the map you just created: 1. Place the cursor inside the limits of the contour map and double-click to display the contour map properties dialog. 2. In the contour map properties dialog, click the Levels tab to display the contour levels and contour line properties for the map. In this example, the contour levels begin at Z = 20. Click on the scroll bar at the right to scroll to the bottom. You can see that the maximum contour level is Z = 105 for this map and that the contour interval is five.

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Go to the Levels page to display the contour level properties. Left-click the column header buttons to change bulk properties. Double-click on individual items to make individual property changes. 3. To change the contour range and interval, click the Level button and the Contour Levels dialog is displayed. This shows the Minimum and Maximum contour level for the map and the contour Interval. The Data Limits of the grid file are also displayed in the Contour Levels dialog. 4. In the Contour Levels dialog, double-click in the Interval box and type the value 10. Click the OK button and the Levels page is updated to reflect the change. The contour interval for the map is now 10. The minimum contour level is Z = 20, and the maximum contour level is Z = 100.

Open the Contour Levels dialog by clicking on the Level button on the Levels page. 5. Click the OK button in the contour map properties dialog and the map is redrawn with the new contour levels.

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The contour map is redrawn using new contour levels based on 10-foot contour intervals.

Changing Contour Line Properties You can double-click any of the elements in the list on the Levels page to modify the individual element. For example, you can double-click an individual Z value in the list to change the Z value for that particular contour level. You can also double-click the line style for an individual level to modify the line properties for the selected level. This provides a way to emphasize individual contour levels on the map. Alternatively, you can click on the column header buttons to make bulk changes at regular intervals. This provides a way to emphasize contours at a regular interval, such as an index contour where every fifth line is bold. Double-click individual elements on the Levels page. Level Double-click on the level value to enter a new Z value for a level. Line Double-click on a line to change the line properties for a level. Fill Double-click on a fill sample to change the fill properties for a level. Label and Hatch Double-click on Yes or No to control the display of contour labels and hachures for a level. To change individual contour line properties: 1. Double-click the contour map to open the contours properties dialog. 2. On the Levels page, double-click the line sample for the contour level at Z = 70 to open the Line Properties dialog. 3. You can select the line color, style, or width for the selected line in the Line Properties dialog. In the Width box, click the up arrow, and change the width value to 0.050 in. (A width of 0.000 in is equivalent to one pixel width.) 4. Click the OK button in the Line Properties dialog, and the Levels page is updated to reflect the change. 5. Click the OK button in the map properties dialog and the map is redrawn. The contour line at Z = 70 is drawn with a thicker line. 19

Double-click on an individual elements on the Levels page of the contour map properties dialog to set specific parameters for the selected level. This example shows the line for the Z = 70 with a width of .030 inches.

The contour line at Z = 70 is wider than the other contour lines on this map after changing the individual line properties. Adding Color Fill between Contour Lines Color fill can be assigned to individual levels in the same way as line properties. Alternatively, you can assign colors based on a gradational spectrum between two colors, or select one of the preset color spectrums. The Levels page in the contour map properties dialog shows a correspondence between a level (the values under the Level button) and a color (the values under the Fill button). The colors are used to fill in the space between the corresponding level and the next higher level. For example, if the contour levels are 20, 30, 40, ..., etc., then the color corresponding to level 20 is used to fill in the space between the level 20 contour and the level 30 contour.

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To display contour fill: 1. Double-click the contour map to open the contour map properties dialog. 2. On the General page, click the Fill Contours check box. Click the Apply button to see the default grayscale color fill between contours. To change the color of the fill: 1. In the contour map properties dialog, Levels page, click the Fill button to open the Fill dialog. 2. In the Fill dialog, click the Foreground Color button to open the Colormap dialog. This dialog allows you to select colors to assign to specific Z values. 3. Click on the left node below the color spectrum and then click on the color Blue in the color palette. The color scale now ranges from Blue to White. Alternatively, you could select a color spectrum from the Presets drop-down list, or by clicking the Load button.

Change the color spectrum properties in the Colormap dialog. 4. (Optional) If you would like the color fill to be transparent, change the Opacity value. 5. Click the OK button to return to the Fill dialog. The Foreground Color button is now displayed as a gradation from blue to white. 6. Click the OK button and the fill colors on the Levels page are updated to reflect the change. 7. Click the OK button and the contour map is redrawn with the blue to white fill.

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The contour map is filled with a blue to white colormap after adjustments are made in the Colormap dialog.

Add, Delete, and Move Contour Labels Contour label locations can be changed on an individual basis. Labels can be added, deleted, or moved. To add, delete, and move contour labels: 1. Right-click on the contour map and select Edit Contour Labels. You can also edit labels of a selected contour map using the Map | Edit Contour Labels command. The cursor changes to a black arrowhead to indicate that you are in edit mode. The contour labels have rectangular boxes around them in edit mode. 2. To delete a label, click on the label and press the DELETE key on the keyboard. For example, left-click on the far left 70 label and then press the DELETE key on your keyboard. 3. To add a label, press and hold the CTRL key on the keyboard and left-click the location on the contour line where you want the new label located. The cursor changes to a black arrowhead with a plus sign to indicate you are able to add a new label. Add a 60 contour label to the lower left portion of the map. 4. To move a contour label, left-click on the label, hold down the left mouse button, and drag the label. Release the left mouse button to complete the label move. Move the 70 contour label on the right portion of the map to the north. To duplicate a label, hold the CTRL key on the keyboard while holding the left mouse button and then drag the label to a new location. 5. To exit the Edit Contour Labels mode, press the ESC key.

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Contour labels can be moved, added, or deleted with the Map | Edit Contour Labels command. Modifying an Axis Every contour map is created with four map axes: the bottom, right, top, and left axes. You can control the display of each axis independently of the other axes on the map. In this example, we will change the contour spacing and add an axis label. 3D maps have an additional Z axis. Additional X, Y, or Z axes can be added to a map with the Map | Add command. To modify an axis: 1. Move the cursor over one of the axis tick labels on the bottom X axis and left-click the mouse. In the status bar at the bottom of the plot window, the words "Map: Bottom Axis" are displayed. The "Bottom Axis" object in the Object Manager is also highlighted. This indicates that you have selected the bottom axis of the contour map. Additionally, blue circle handles appear at each end of the axis, and green square handles appear surrounding the entire map. This indicates that the axis is a "sub-object" of the entire map. 2. Double-click on the bottom axis to display the bottom axis properties dialog. 3. In the Title box on the General page, type "Bottom Axis" (without quotes) and then click the Apply button. This places a title on the selected axis.

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If you would like to edit other axes, click on the axis. You do not need to close the dialog before changing your selection.

4. If you cannot see the axis title, select View | Zoom | Selected. Notice that you do not have to close the properties dialog to select menu commands, toolbar buttons, or objects in the plot window. 5. Click on the Scaling tab to display the axis scaling options. In the Major Interval box, type the value 1.5 and then click the Apply button. This changes the spacing between major ticks along the selected axis. 6. Click on the General tab and then click the Label Format button to open the Label Format dialog. 7. In the Label Format dialog, select the Fixed option in the Type group. Click on the down arrow on the Decimal Digits box and change the value to 1. This indicates that only one digit follows the decimal point for the axis tick labels. 8. Click the OK button to return to the axis properties dialog. 9. Click the OK button in the axis properties dialog and the map is redrawn. The axis tick spacing and labels are changed, and the axis title is placed below the map.

You can use the axis properties to change the tick mark and axis title properties

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Saving a Map When you have completed the map in the plot window, you can save the map to a Surfer file [.SRF] containing all the information necessary to reproduce the project. When you save a map as a [.SRF], all the scaling, formatting, and map properties are preserved in the file. An asterisk (*) next to the file name in the title bar and tab indicates the file has been modified and the modifications have not yet been saved. To save a map: 1. Choose the File | Save command, or click the button. The Save As dialog is displayed because the map has not been previously saved. Select a directory that you have the ability to save to. 2. In the File name box, type TUTORWS. 3. Click the Save button and the file is saved to the current directory with an [.SRF] extension. The saved map remains open and the title bar changes to reflect the name change. There is no longer an asterisk next to the file name. To export contour lines to 3D DXF, 2D SHP, or 3D SHP: 1. Select the map by clicking on the map in the plot window or by clicking on the word "Contours" in the Object Manager.

Select the contour map by clicking on the Contours object in the Object Manager or by clicking on the map in the plot window.

2. Choose Map | Export Contours. 3. In the Save As dialog , type TUTORWS into the File name box, specify AutoCAD DXF File (*.dxf), 2D ESRI Shape File (*.shp), or 3D ESRI Shape File (*.shp) in the Save as type box. 4. Click Save and the file is exported to the current directory. This creates a file titled TUTORWS.DXF or TUTORWS.SHP depending on what file type you selected.

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Lesson 4 – Post Maps and Working with Map Layers What are post maps? Post maps are created by placing symbols representing data points at the X, Y data point locations on a map. What are post maps used for? Posting data points on a map can be useful in determining the distribution of data points, as well as placing data or text information at specific points on the map. Data files contain the X, Y coordinates used to position the points on the map. Data files can also contain the labels associated with each point. What are map layers used for? Map layers allow you to add multiple maps to an existing map to create one map object displaying a variety of map types. The layers use a single set of axes and are positioned according to the composite coordinate system. For example, if you have a contour map of weather data created, you can add a post map layer displaying the location and station names of each data collection station. How are map layers added to existing maps? Map layers can be added to an existing map by selecting the map and using the Map | Add command or by dragging an existing map layer from one map object to another

Adding a Post Map Layer To add a post map layer to the current tutorial map: 1. Using the TUTORWS.SRF file you created in the previous lesson, select the contour map. 2. Select the Map | Add | Post Layer command, or right-click on the contour map and select Add | Post Layer. 3. In the Open Data dialog, select TUTORWS.DAT from the SAMPLES folder. 4. Click the Open button and the post map layer is added to the contour map. Notice in the Object Manager that the post map layer has been added to the contour map the two maps now share the same set of axes. Changes made in the map properties dialog will affect the contour map layer and the post map layer.

Changing the Post Map Properties Once you have created a post map layer, you can customize the post map properties. To change the post map properties: 1. Make sure the Object Manager is open. If the Object Manager is not open, choose View | Object Manager. 26

2. Double-click on the word "Post" in the Object Manager, or right-click on the word "Post" and select Properties or choose edit| Properties. 3. In the post map properties dialog General page, click the Default Symbol button to open the Symbol Properties dialog. 4. Choose the filled diamond symbol (Symbol set: Default Symbols, Number: 6) from the symbol palette or any other symbol. 5. Choose the color, and Opacity can be adjusted to create semi-transparent symbols. 6. Click the OK button. The selected customized symbol appears as the Default Symbol button. 7. Click the Apply button and the symbol appears at the posted data points on the map. 8. In the Fixed Size box (Symbol Size group), specify a size of 0.09 in. Alternatively, symbol size can be controlled by proportional scaling (optional). 9. Click the OK button and the post map is drawn with the custom symbol. If the post map is not visible, ensure that the post layer is on top of the contour layer in the Object Manager. The order the layers are listed in a map object is the order the map layers are drawn in the plot window. To move a map layer, left-click and drag up or down in the map object. Alternatively, select the map layer and use the Arrange | Order Objects command or right-click and select Order Objects

Selecting a Map Layer and Changing the Object ID After creating a multi-layer map with a post map layer and a contour map layer, you can still modify the individual map layers. Selecting Map Layers An individual map layer can be selected in the multi-layer map by selecting a map layer in the Object Manager. Renaming the Map Layers 1. Click the contour map layer name in the Object Manager. In this case, click the word "Contours." The status bar should now report "Map: Contours." 2. Choose Edit | Object ID. 3. In the Object ID dialog, type the name "Tutorial Contour Map" and click the OK button. The status bar, Object Manager, and properties dialog title reflect the name change.

Enter a new object name in the Object ID dialog. 4. Repeat steps 1-3 and rename the post map layer to "Tutorial Post Map".

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Left-click the word Post in the Object Manager to select the post map layer.

Adding Labels to the Post Map You can add labels to the data points on post maps. The post map can be selected by a few different methods, though only the Object Manager method is discussed here. To add labels: 1. Right-click on the "Tutorial Post Map" layer in the Object Manager and select Properties. 2. Click on the Labels tab. In the Worksheet Column for Labels group, click the drop-down arrow and a list of columns in TUTORWS.DAT are displayed. 3. Select Column C: Elevation from the list. 4. Click the Format button to open the Label Format dialog. 5. Change the Type to Fixed and the Decimal Digits value to zero. 6. Click the OK button to return to the post map properties dialog, Labels page. 7. Click the OK button and the post map layer is redrawn with labels on each of the data points.

Add

labels to post maps through the post map properties dialog.

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Lesson 5 - Creating a 3D Surface Map What is a 3D Surface Map? Surfaces are similar to 3D wireframes, except that surfaces are three-dimensional shaded renderings of a grid file. What is a 3D Surface Map Used For? Surfaces provide an impressive visual interpretation of data. Surfaces can be layered with other surfaces, so that the surfaces will intersect with each other. Surfaces can also have layers of other map types, excluding 3D wireframes. Surfaces allow you to generate an elevation model of your area of interest and then add layers of data on the top of the surface. You can control the color, lighting, overlay blending, and wire mesh grid of a 3D surface. For example, if you have location (X, Y) and temperature (Z) data for a region and you have the same location (X, Y) and corresponding elevation (Z) data for the area, you could create a grid file with the Z variable being elevation and a grid file with the Z variable being temperature. You could create a 3D surface of the elevation grid to represent topography, then add a contour map of the temperature variation. You could continue to add map layers, such as a classed post map layer with the temperature collection stations that have different symbols depending on the elevation. To create a 3D surface map: We are going to use the same grid file you used to created the tutorial contour map. The 3D surface map will provide a new perspective to the contour map you have already created. 1. Select the File | New | Plot command to open a plot document. 2. Select the Map | New | 3D Surface command, or click the button. 3. Choose the grid file TUTORWS.GRD from the list of files in the Open Grid dialog. The TUTORWS.GRD, created in Lesson 2 - Creating a Grid File, is located in Surfer's SAMPLES folder. 4. Click the Open button, and the 3D surface is created using the default settings.

Adding a Mesh Mesh lines can be applied to surfaces. 3D surface maps have more capability than 3D wirframe maps. Adding mesh lines to a 3D surface map simulates a 3D wireframe map. To add a mesh: 1. 2. 3. 4. 5.

Double-click on the 3D surface map to open the 3D surface properties. Click the Mesh tab. Check the X and Y boxes in the Draw Lines of Constant section. Change the Frequency to five for the X and Y lines. Click the OK button or the Apply button to add a mesh to the selected 3D surface.

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Changing Colors Changing color schemes on 3D surfaces is similar to changing colors on other map types such as image maps or contour maps. The Colormap dialog is used to load previously defined color schemes, or to create your own color schemes. To change the surface material color: 1. Double-click on the 3D surface to open the 3D surface properties dialog. 2. On the General page, click the Upper button in the Material Color group. The Colormap dialog opens. 3. In the Colormap dialog, select Rainbow from the Presets drop-down list. The Presets list contains a variety of predefined color schemes. Alternatively, you can click the Load button and select a custom color spectrum file with a [.CLR] extension. The COLORSCALES folder contains many sample [.CLR] files. 4. Notice that the colors and anchor node positions have changed in the Colormap dialog. The Rainbow preset has six nodes that range from purple to red. You can add, remove, apply opacity, customize the nodes, or accept the default selections. 5. Click the OK button in the Colormap dialog to return to the 3D surface properties dialog. 6. Click the Apply button in the 3D surface map properties dialog to see your color changes. You can continue to experiment with the colors by opening the Colormap dialog and selecting other color spectrum files from the Presets drop-down list or by loading custom color files.

This is a 3D surface map with a mesh displayed at a frequency of five. The 3D surface map is using the preset Rainbow color spectrum.

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Lesson 6 - Adding Transparency, Color Scales, and Titles What are transparencies? The opacity of a map, image, text, line, fill, symbol, or entire layer can be customized in Surfer. By default, objects are displayed with 100% opacity. An object can be made semitransparent by adjusting the opacity value. What are transparencies used for?

Reducing the opacity of an object allows the ability to see through the object to other objects. This may be useful when wanting to create a semi-transparent map or object. For example, you may want to display a semi-transparent contour map over a base map of a satellite image. What are color scales? Color scales are available for contour, 3D wireframe, 3D surface, image, and vector maps. They are legends that show the fill assigned to each contour level on a filled contour map, the colors assigned to levels in a 3D wireframe, the colors used in an image map, or 3D surface, and the fill assigned to vector symbols. How can these features improve the final map? Having a completed map with multiple layers, color scale legends, and titles allow you to provide well organized and easily understandable publication quality maps. Creating a Contour Map To create a contour map: 1. Select the File | New | Plot command, or click the button. A new empty plot window is displayed. 2. Select the Map | New | Contour Map command. 3. Choose the grid file TUTORWS.GRD from the list of files in the Open Grid dialog, click the Open button, and the map is created using the default settings. The TUTORWS.GRD, created in Lesson 2 - Creating a Grid File, is located in Surfer's SAMPLES folder.

Adding Transparency to Map Layers You can adjust the Opacity value of a map layer, or of individual contour fill, polygon fill, text, lines, or symbols in the appropriate properties dialog. This may be useful when you have multiple map layers and need to make one or more layers semi-transparent to best represent your data.

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To add transparency to a contour map: 1. 2. 3. 4. 5. 6. 7.

Open the contour properties dialog. On the Levels page, click the Fill button. In the Fill dialog, click the Foreground Color button. In the Colormap dialog, select Rainbow from the Presets drop-down options. Change the Opacity to 43%. Click the OK button to return to the Fill dialog. Click the OK button to return to the Levels page of the contour properties dialog. The Fill column displays the change in opacity. 8. Click the OK button and the map is drawn with semi-transparent contour fill.

Adding a Shaded Relief Map Layer Adding a shaded relief map layer to our existing semi-transparent map will help display the elevation behind the contour fill. To add a shaded relief map layer: 1. Click on the contour map once to select it. 2. Select Map | Add | Shaded Relief Layer command. 3. Select the file TUTORWS.GRD, and click the Open button. A shaded relief map layer is added to the map object in the Object Manager. Notice how the shadows of the shaded relief map layer help distinguish the topography of the grid file. 4. (Optional) In the Object Manager, you may want to click the check mark next to the Contours or Shaded Relief Map layers to toggle the visibility of the maps on and off.

Adding a Color Scale You can add a color scale to contour, 3D wireframe, 3D surface, image, and vector maps. To add a color scale to the contour map: 1. Open the contour map properties. 2. Click the General page, be sure the Fill Contours options is checked. Then, click the Color Scale check box. 3. Click the OK button and a default color scale is created. A new Color Scale object is added to the Object Manager. To change the color scale properties (optional): 1. Double-click the scale bar to display the Color Scale Properties dialog. 2. Make adjustments to the label or line properties. 3. Click the OK button to redraw the color scale bar with updated properties. To add a title to the color scale bar (optional):

1. Use the Draw | Text command and click to the left of the scale bar. The Text Properties dialog opens. 32

2. In the Text section, enter "Elevation (Meters)", and click the OK button. Click the ESC to exit the text edit mode. 3. Select the text object and use the Arrange | Rotate command. In the Rotate dialog, enter "90" in the Clockwise rotation in Degrees box. Click the OK button. 4. Position the rotated text to line up with the color scale. 5. Select the color scale and the text in the Object Manager by selecting the first object, holding the CTRL key, and selecting the second object. Once only those two objects are selected, use the Arrange | Group command to create a composite object. 6. Rename the composite object to "Tutorial Color Scale".

Adding a Map Title Adding a title to a map is a great way to stay organized and create publication quality maps. To add a title to the tutorial map: 1. 2. 3. 4. 5.

Open the top axis properties of the tutorial map you have created. Click on the General tab in the top axis properties dialog. In the Titile section, type "Tutorial Map" without the quotes. Press the ENTER key to move to the next line. On the second line, we will use a dynamic predefined math text instruction to insert the current date. In this case we will use the term "\date " to display the current date. Be sure to add a space at the end of "\date ". Failure to put a space after "\date " will result in a math text instruction error. 6. Click the Font button in the Title section to open the Font Properties dialog. Click the check box next to Bold in the Style section. Change the Size (points) to 14. 7. Click the OK button to return to the General page of the top axes properties dialog. 8. Click the OK button to redraw the map with the new map title.

This map contains a semi-transparent contour layer on top of a shaded relief layer. A color scale and title were added to the map.

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IPI2win Program: 1D interpretation of VES data 1. Introduction Electrical resistivity is a physical property of a material that describes its ability to resist the flow of electrical current. The resistivity method is, therefore, based on the principle that the voltage drop associated with DC or low frequency current injected into the soil is strongly dependent on the resistivity of the soil. As electrical conduction takes place as a result of the movement of the ions, electrical properties of soils are mainly controlled by pore water content. However, the solid phase characteristics affect the relative proportions of water and the air and the connectivity of pores. Furthermore, the electrolytic current conduction is affected by the temperature and pore water salinity. The theoretical background of the resistivity method, common electrode arrangements, measurement procedures can be found in several textbooks ( Keller and Frischknecht, 1966; Telford et al., 1990; Reynolds, 1997). The resistivity method is one of the oldest geophysical survey techniques. The purpose of electrical surveys is to determine the subsurface resistivity distribution by making measurements on the ground surface. From these measurements, the true resistivity of the subsurface can be estimated. The ground resistivity is related to various geological parameters such as the mineral and fluid content, porosity and degree of water saturation in the rock. Electrical resistivity surveys have been used for many decades in hydrogeological, mining, geotechnical, environmental and even hydrocarbon exploration (Loke et al., 2013). 1.1 Electrical resistivity method: Basic theory The four-electrode resistivity method is based on the principle that the potential drop across a pair of electrode (P1 and P2) associated with DC or low frequency current injected into the soil using another pair (C1 and C2) (Figure 1), is proportional to the soil resistivity, that is:

Where, ρ is the soil resistivity (Ohm.m), ∆V is the voltage difference (Volts), I is the current (Amps), and K is a geometric factor (m) that accounts for the electrode arrangement.

Figure (1): Electrical resistivity method

1

In a homogeneous medium, the measured resistivity from is constant and independent on the electrode configuration or location. In a heterogeneous medium, the measured resistivity is then termed the apparent resistivity (Keller and Frischknecht, 1966), which is the resistivity of an equivalent homogeneous medium that will give the same resistance value for the same electrodes arrangement . Therefore, the measured resistivity value is an average reading of the soil volume engaged during the measurements. This equation is the general equation for calculating the resistivity of any electrode arrangement. Figure 2 shows the common arrays used in resistivity surveys together with their geometric factors. To determine the true subsurface resistivity from the apparent resistivity values is an “inversion” problem.

Figure (2) Popular electrode arrangements. C1 and C2: Current electrodes, P1 and P2: Voltage electrodes, a is electrode spacing, n is spacing integer factor. 1.2 Resistivity Data acquisition Traditional four-electrode resistivity system consists of a resistivity meter, four metal stakes (electrodes) and cables to connect the electrodes to the resistivity meter. The system includes two essential components: the power unit and the voltage measuring unit connected to the current and voltage electrode through the cables. Figure (3) shows the basic parts of the traditional fourelectrode resistivity system.

Figure (3) Traditional four-electrode resistivity system

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Traditional 1D data acquisition is carried out using Vertical Electrical Sounding (VES), horizontal profiling or Constant Separation Traversing (CST) and horizontal mapping, Figure (4). VES can be performed by taking a number of measurements at a fixed array midpoint, where distances between the electrodes are progressively increased to obtain the resistivity variation with depth Figure (5). Interpretation of VES curves assumes 1D horizontally layered resistivity models. This method has traditionally been used in hydrogeological and engineering applications for delineating the depth of bedrock, the water table and the thickness of horizontal layers. CST is achieved by moving an array with fixed electrode spacing along a profile to detect the lateral resistivity variations Figure (6). The measurements obtained are interpreted qualitatively to map the location of vertical structures, such as faults, and to map the thickness of overburden layers. Horizontal mapping (combining several CST profiles) is useful to map lateral resistivity variations.

Figure (4) VES and CST

Figure (5) Vertical electrical sounding curves

Figure (6) Horizontal resistivity profiling.

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By combining vertical electrical soundings and profiling/mapping, a 2D/3D subsurface resistivity images can be obtained. This technique is commonly named a continuous vertical electrical sounding (CVES) or electrical resistivity imaging (ERI) or electrical resistivity tomography (ERT) . In this mode, number of electrodes are installed at a regular distance along a line and connected to the resistivity meter through multi-core cable. The measurements are progressively recorded for particular electrodes spacing (a) and for a number acquisition (n) levels (i.e. multiple of minimum electrode spacing). Figure (7) shows electrode arrangements for 2D resistivity data collection using Wenner array (Loke, 2015).

Figure (7) The arrangement of electrodes for a 2-D electrical survey and the sequence of measurements. 1.3 1D Resistivity Data Interpretation The resistivity method has its origin in the 1920’s due to the work of the Schlumberger brothers. For approximately the next 60 years, for quantitative interpretation, conventional sounding surveys were normally used. In this method, the center point of the electrode array remains fixed, but the spacing between the electrodes is increased to obtain more information about the deeper sections of the subsurface. The measured apparent resistivity values are normally plotted on a log-log graph paper. To interpret the data from such a survey, it is normally assumed that the subsurface consists of horizontal layers. In this case, the subsurface resistivity changes only with depth, but does not change in the horizontal direction. A one-dimensional model of the subsurface is used to interpret the measurements (Figure 8). This method has given useful results for geological situations (such the water-table) where the one-dimensional model is approximately true. The greatest limitation of the resistivity sounding method is that it does not take into account lateral changes in the layer resistivity. The failure to include the effect of such lateral changes can results in errors in the interpreted layer resistivity and/or thickness. Therefore, 2D/3D models offer more reasonable interpretations.

Figure (8) The three different models used in the interpretation of resistivity measurements.

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2. IPI2win program (Geoscan-M Ltd., 2002)

IPI2win is a free computer program for 1D interpretation of VES curves. Besides normal resistivity surveys, it also supports interpretation of IP (induced polarisation) data. Figure (9) shows the subsurface model used in the 1-D sounding method. The layers are horizontal layers that have two parameters, the layer resistivity ρ and thickness h (except for the last layer that is assumed to extend infinitely downwards). VES curves could be analyzed with different arrays: Schlumberger, Wenner, and pole - pole. Figure (10) shows VES data (10).

Figure (9) A typical 1-D resistivity model.

Figure (10) 1-D model of vertical resistivity sounding data. 2. 1 Installing and starting the program The IPI2win package comes in a single compressed installation file SETUP.EXE that is a Windows based installation program. The following screen (Figure 11) will be displayed.

Figure (11) IPI2win home screen

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2.2 IPI2Win home screen On the home screen, three windows are displayed (Figure 11): 1. Apparent resistivity curve window. 2. The model window. 3. Pseudo cross-section and resistivity section window. The user can rearrange these windows using Window menu. 2.3 The main steps for using IPI2Win The main steps for using IP2Win are: Data input, Data inversion, Adding data points to create pseudo and resistivity cross sections. Data input can be done directly from AB/2, V, I, and K data or AB/2 , data. The outputs are resistivity graph, resistivity‐layer thickness table, and pseudo cross section. Basic weakness of IP2 Win software is a bug that frequently occurs when analyzing data. That problem can be solved by restarting software. The data collected from a 1-D resistivity sounding survey consists of the electrode spacings used and the corresponding apparent resistivity values. The purpose the inversion is to determine the thickness and resistivity of the layers of a 1-D model that will produce a model response that matches the measured values. In this method, an initial model is created, and the program modifies the thickness and resistivity of the layers so as to reduce the difference between the calculated and measured apparent resistivity values, see Figure (12). Adding data points can be used to create pseudo and resistivity sections.

Figure (12) Interpretation of 1D VES data 2.3.1 VES data Input in IPI2Win 1. Run IPI2Win program and click File>New VES point or click New VES window will come out, see Figure (13).

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button on the toolbar. A new

Figure (13) New VES window *AB/2 column is used for the distance between the current electrodes, MN column is used for the distance between the voltage electrodes. * SP is used for self potential data input, V for inputting voltage data, I for inputting electric current data, and K is the geometric factor data. Rho_a column is apparent resistivity data column (Rho_a is the result from electrical resistance and geometric factor calculation value). 2. Choose the electrode array (Schlumberger for example) and apparent resistivity input. 3. Input the data (Ab/2 and Rho_a) as in the example (Figure 14). Points will be plotted in the graph.

Figure (14) VES data input

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4. Click OK to save the Data. (Note: Data can be saved in*.txt format by clicking Save TXT button). 5.Save as window will come out to decide where the data will be saved as VES data file. Give it a name, as example “Test”. Click Save button. Curves and table will be displayed (Figure 15).

Figure (15) VES Curves Note: The table gives the resistivity of each layer displayed in ρ column. Layer thickness is displayed in h column. Layer depth from surface is displayed in d column. Alt column is altitude column or depth from VES point elevation (the example showed VES value elevation in 0 m so Alt value is ‐1.5 m, if VES elevation value in 5 m then Alt value will be 3.5 m). Data error is displayed on table title bar (error level in the example above is about 23.5%). Data error can be corrected automatically by clicking Point>Inversion. Manual data correction can be done by dragging the curve. 2.3.2 VES data inversion in IPI2 Win 1.Choose Point >Inversion command or click inversion button on the toolbar . The results will be displayed and error value on table title bar will be changed, as shown in Figure (16) (note: there was a value decreasing from 23.5% to 6.82 %). Black curve shows the observed data. Red curve shows the calculated curve and Blue curve gives information about resistivity variations. 2.Close IPI2 Win software by clicking File>Exit or Exit button on the toolbar. Note: Every change made in IPI2 Win will be automatically saved. Run IPI2 Win software again to input another VES point data.

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Figure (16) Inversion results 2.3.3 Joining VES Data and Creating Pseudo and Resistivity Cross Sections 1.Re run IPI2 Win program. Click File>Open. Open Data File Window will appear, choose the previous saved VES file as example “Test”, and then click open. VES Curves and Table will come out. 2. Click File>Add file for joining another VES data, see Figure (17).

Figure (17) Adding VES file

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3.Open data file window will appear. Choose another saved VES file as example “Test 2”. Click Open. The VES file will be joined with previous VES file ''Test''. 4. Save United Profile window will appear, give a name for the file and click Save button. 5. Information window will appear, Figure (18). N column is the number of joined VES point. VES names column is name of each VES point (can be changed by clicking the VES_name in VES names column). X is distance between united VES points and Z is elevation of each VES points. Choose Array type and click OK.

Figure (18) Information window of the joined VES files 6. Pseudo Cross Section and Resistivity Cross Section will be displayed, see Figure (19).

Figure (19) Pseudo Cross Section and Resistivity Cross Section

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2.3.4 Pseudo Cross Section and Resistivity Cross Section Options Pseudo Cross Section and Resistivity Cross Section can be changed by clicking on Section>Options or button on the toolbar. Section options window will appear (Figure 20). The user can change axis labels, contour levels, color scale, print scale, titles,... etc.

Figure (20) Section options window 2.3.5 Sections export Click on File>Export. Data can be exported in another file formats such as Surfer, QWSELN, BMP and Res2dInv, See Figure (21). For exporting section, curve, and table in image format (BMP), choose BMP. When choosing BMP, choose the part that will be exported then click Save button, Figure (22).

Figure (21) Sections export

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Figure (22) BMP export

Save As window will appear. Decide the location where the image file will be stored, give it a name, and click Save button. 2.3.6 Printing VES curve and resistivity sections VES Curves and resistivity sections can be printed using File>print curves and File>section commands, respectively. References: - Geoscan-M Ltd. (2002). IPI2Win User Manual. -Keller, G. V. and Frischknecht. F.C. (1966). Electrical methods in geophysical prospecting. New York: Pergamon Press. -Loke, M. H. (2015). Tutorial: 2-D and 3-D electrical imaging surveys. http://www.geotomosoft.com/coursenotes.zip. -Loke, M. H., Chambers, J. E., Rucker, D. F., Kuras, O. and Wilkinson, P. B. (2013). Recent developments in the direct-current geoelectrical imaging method, Journal of Applied Geophysics, 95, pp. 135-156. -Reynolds, J. M. 1997. An introduction to applied and environmental geophysics. Chichester: John Wiley & Sons. -Telford, W. M., Geldert., L. P. and Sheriff, R. E. 1990. Applied geophysics. Cambridge University Press., Cambridge, UK.

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