Fault Mapper 3.2 User Manual by Roberto Basili basili_r@ingv.it Istituto Nazionale di Geofisica e Vulcanologia Via di Vigna Murata 605 - 00143 Roma ITALY phone: +39 0651860516 http://www.ingv.it/~wwwpaleo/basili_r/downloads.htm

FaultMapper is a Microsoft Excel® workbook, supplied with a few VBA macro commands, that allows easy manipulation of the basic parameters of a rectangular fault-plane and obtain the geographic coordinates of its end-points. This document will guide the user through the main functionalities of FaultMapper, however it is assumed that the user is already familiar with the MsExcel® basic commands. None of the MsExcel® functions and tools are inhibited in the workbook, therefore all the worksheets can be customised at the user convenience. Intuitive tools aid with the manipulation while the main kinematic and seismological properties of the fault are automatically updated and shown in a summary table. A plot of the fault-plane projection in a geographic context is simultaneously displayed in the same window. A stereographic projection of the theoretical focal mechanism displays in the upper-right corner of the map.On startup a dialog box warns that the file contains macros. Click the button "enable macros" to activate the FaultMapper functionalities. Five worksheets are provided with the workbook: (1) "read_me", (2) "data_in", (3) "FM", (4) "cmpt", and (5) "Fault_File", containing respectively: the text of this user manual; FaultMapper input tables and diagrams; FaultMapper output tables and diagrams; formulas, variables and constants for all calculations; and results saved by the user.

The "data_in" worksheet contains two frames. The "FAULT DATA INPUT" frame, on the right-hand side, contains the input fields that have to be filled-in by the user. The "MAP AND CROSS-SECTION" frame, on the left-hand side, displays the current fault plane in map and vertical section views. After having set the fault initial parameters use the "Go to Map" button to go ahead with the "FM" worksheet functions.

The "FM" worksheet contains four frames. The "MAP AND CROSS-SECTION" frame, on the upper-right corner, displays the current fault plane in map and vertical section views. When the fault parameters are modified the initial fault turns to light red/blue, while the final fault remains dark red/blue. The "ADJUSTMENTS" frame contains tools for modifying the fault parameters. The "RESULTS" frame contains a table that lists all input and derived fault parameters. The "LOCATION MAP" frame contains a plot of the fault in a geographic context and the focal mechanism associated with the fault.

This worksheet contains also six buttons. The "Append to Fault File" button allows the user to save the results of the manipulations. Each time this button is pressed, the significant parameters of the current fault are appended to the "Fault_File" worksheet in reverse order (last fault first=upper). Each resulting set can be identified by setting the fault identifier "ID" appropriately. The "Clear Fault File" button returns an empty "Fault_File" worksheet. Similarly, a plot of the fault may be saved in the geographic diagram by pressing the "Map Fault" button, which also turns the mapped fault to yellow. The "Clear Map" button returns an empty map. Notice that both the "Clear Fault File" and "Clear Map" buttons erase all the faults.

The "read_me", "data_in", and "FM" worksheets are write-protected to prevent accidental modifications. To first enter and then manipulate the fault parameters the user must fill-in the green cells in the "FAULT DATA INPUT" frame and use the appropriate tools in the "ADJUSTMENTS" frame. Before make any change in these three worksheets the protection must be deactivated using the "Tools>Protection>Unprotect sheet…" command (no password is needed). Notice that the "cmpt" and "fault_file" worksheets are not protected. The user is cautioned that any accidental modification in the "cmpt" worksheet will permanently alter the program functionalities.

The "FM" worksheet is designed for high quality monitor display (e.g. 19 inch screen with 0.27 dot pitch, 1024x768 resolution, 32 bit colours). FaultMapper may not display well on a lower quality monitor. To improve readability, especially with portable computer monitors, lower the zoom factor.

Formulas used in the "cmpt" worksheet contain approximations. Use of this worksheet to calculate geographic coordinates of objects larger then about 50 km may result in significant errors.
 

2. Data input

This section describes the operations that can be done in the "data_in" worksheet. It is assumed that the data input process starts with data coming from geological observations. The program asks for the location of the fault cut-off tips. There are two possible ways of entering these data: (1) the "one tip" method, when the location of one tip, azimuth and length are known; (2) the "two tips" method, when location of two tips is known. Select the appropriate option/button to activate the desired method.

Four different options for entering data in the depth dimension can be selected from the list box: (1) Dip, Width, Top, when the dip, down-dip width and depth of upper fault edge are known; (2) Dip, Width, Bottom, when the dip, down-dip width and depth of lower fault edge are known; (3) Dip, Auto-Width, Top, when only the dip and depth of upper fault edge are known; (4) Dip, Auto-Width, Bottom, when only the dip and depth of lower fault edge are known. Select one of these options to activate the desired method.

It is recommended that a fault identification number be always set to identify the fault in the "fault_file" after the processing is over. The following table provides a description of all keys in the "data_in" worksheet.

3. Manipulation and results

This section describes the basic operations that can be done in the "FM" worksheet. Several scroll bars allow the user to make incremental adjustments for all parameters entered in the "data_in" worksheet, such as:

• move north-south; 
• move east-west; 
• rotate horizontally clockwise and counter-clockwise; 
• rotate vertically, i.e. increase and decrease dip; 
• lengthen and shorten; 
• enlarge and reduce (width-wise); 
• move up-down (towards-away from surface); 
• change angle of slip; 
• increase-decrease amount of slip.