DOI: 10.4231/a5xq-7k89
title: Alpine Fault Drilling DFDP-2B, South Island, New Zealand: Updated analysis of full waveform sonic log data

description: &lt;p&gt;This repository holds the data and code used in the reanalysis of the full waveform sonic log data obtained in the DFDP-2B borehole drilled in the Whataroa Valley, South Island, New Zealand to study the structure of the Alpine Fault.  The borehole transits primarily through the hanging wall damage zone of the fault.   The logging was accomplished by the logging team from Montpelier University, France. &lt;/p&gt;

&lt;p&gt;These data are supplemental to Dr. Oumeng Zhang&#39;s PhD thesis: THEORY MEETS TERRAIN: ADVANCING THE ALPINE FAULT INSIGHTS WITH SEISMIC ANISOTROPY INVERSION [PhD, Purdue University ]. West Lafayette, 2024.  https://doi.org/10.25394/PGS.25569297.v1&lt;/p&gt;

&lt;p&gt; &lt;/p&gt;

&lt;p&gt;The zipped archive contains the following files or folders:&lt;/p&gt;

&lt;ul&gt;
 &lt;li&gt;&lt;strong&gt;README_Sonic_PURR.docx&lt;/strong&gt;:  This document provides a detailed explanation of all of the files and the programs developed to analyze the full waveform records as listed below. This includes a link to the original data repository at the International Continental Drilling Program.  Briefly, the folder contains:&lt;/li&gt;
 &lt;li&gt;A SLB VISTA&lt;sup&gt;TM&lt;/sup&gt; seismic data processing project &lt;strong&gt;Alpine_Fault_Sonic.vwn &lt;/strong&gt;and associated files within the larger folder&lt;strong&gt; Vista Project.  &lt;/strong&gt;This contains the original and processed sonic log data, and the time picks were made using modules in this program.  Note that the VISTA software package is commercial and readers will need access to it to work with the data in this format.  However, the main raw and processed data are put in the readily accessible SEGY 1.0 format in *.sgy files mentioned next. &lt;/li&gt;
 &lt;li&gt;The full waveform log data provided in SEGY v1.0 format of:&lt;/li&gt;
&lt;/ul&gt;

&lt;ol&gt;
 &lt;li&gt;&lt;strong&gt;FWScR49d.sgy&lt;/strong&gt;: the raw 4-channel full waveform data. &lt;/li&gt;
 &lt;li&gt;&lt;b&gt;&lt;span style="font-size:12.0pt"&gt;&lt;span style="line-height:115%"&gt;&lt;span new="" roman="" style="font-family:" times=""&gt;FWS_PredDecon_PStimes.sgy &lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/b&gt;: the data corrected for polarity on Channel 3 and after application of predictive deconvolution to eliminate reverberations.&lt;/li&gt;
 &lt;li&gt;&lt;strong&gt;Picked_PS_April_11_2024.asc : &lt;/strong&gt;the manually picked P and S wave arrival times (in ms) from the analysis of &lt;span style="font-size:12.0pt"&gt;&lt;span style="line-height:115%"&gt;&lt;span new="" roman="" style="font-family:" times=""&gt;&lt;strong&gt;FWS_PredDecon_PStimes.sgy&lt;/strong&gt; from the SLB VISTA project.   &lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/li&gt;
&lt;/ol&gt;

&lt;ul&gt;
 &lt;li&gt;Matlab *.m programs include:&lt;/li&gt;
&lt;/ul&gt;

&lt;ol&gt;
 &lt;li&gt;&lt;strong&gt;quickLASread.m&lt;/strong&gt; (function): This is a short script that allows one to ready a standard well log LAS file simply.&lt;/li&gt;
 &lt;li&gt;&lt;strong&gt;Run_velocity_find.m&lt;/strong&gt;: Program to convert the picked transit times from &lt;strong&gt;Picked_PS_April_11_2024.asc &lt;/strong&gt;converting them to P and S wave velocities that are saved in the matlab data file &lt;strong&gt;Sorted.mat&lt;/strong&gt;.&lt;/li&gt;
 &lt;li&gt;&lt;strong&gt;Picks2Vel_Figure.m:  &lt;/strong&gt;using input&lt;strong&gt; Sorted.mat &lt;/strong&gt;this program also calculates the P and S wave speeds and their statistics various ways then saves these to text files &lt;strong&gt;Pwave_vels.txt&lt;/strong&gt; and &lt;strong&gt;Swave_vels.txt &lt;/strong&gt;and then plots them.  The program also reads in the LAS format file  &lt;strong&gt;Tilt_Az_Run47.LAS&lt;/strong&gt; that contains the borehole tilt and azimuth (as obtained from the systems on the acoustic borehole televiewer) and uses this to calculate for purposes of comparison the anisotropic P and S wave speeds for the intact rock without any fractures.  This program finally produces and outputs the figure &lt;strong&gt;Velocity_Figure.png&lt;/strong&gt; that reproduced in the thesis.&lt;/li&gt;
 &lt;li&gt;&lt;strong&gt;sgyread.m&lt;/strong&gt; can be used to read the raw *.sgy files into Matlab if so desired.  Note that there are many other such matlab and python based codes readily available on the internet that can also do this job.&lt;/li&gt;
&lt;/ol&gt;

&lt;ul&gt;
 &lt;li&gt;Figures for the thesis and paper are archived also in the CorelDraw&lt;sup&gt;TM&lt;/sup&gt; file &lt;strong&gt;Sonic_Log_Figures.cdr&lt;/strong&gt;&lt;/li&gt;
&lt;/ul&gt;
description: This repository contains raw and processed full waveform sonic log data obtained in the Alpine Fault drilling program DFDP-2B borehole. Subsequent processing of these waveform data allow for determination of transit times and these data are plotted.