SR1703 Knudsen sub-bottom profiler data

This folder contains single-channel subbottom profiling data (CHIRP) collected offshore of Southern California between San Diego and Dana Point focused on the San Diego Trough fault aboard the R/V Sally Ride in February 2017. Contents: processed segy data, navigation files (WGS-84), line plots The primary chirp survey for this project was conducted during a coring shake-down cruise on the R/V Sally Ride under Captain Ian Lawrence between February 3-11th, 2017. Chief Scientist Mitch Lyle graciously allowed us to run seismic profiles overnight between coring operations. The surveys were conducted by Hector Perea and Neal Driscoll (SIO), with Bormann (UNR/CSULB) remotely planning and monitoring data collection from shore. This survey resulted in 32 new profiles totaling 280 line-km of ultrahigh-resolution sub-bottom profiles (Figure 2 - magenta grid). The data were acquired using the hull-mounted Knudsen Chirp 3260 Echosounder operated at 3.5 khz. The survey speed ranged between 4.0-5.5 knots with a 3-second shot interval. The reflected waveforms were sampled at 0.06 ms intervals for a 0.267-second window that auto-tracked the seafloor. The signal penetrated between 0.6-1 seconds of two-way-travel-time beneath the seafloor, imaging reflectors in the upper 45-70 m of sediment (all sub-bottom depths and stratal thicknesses estimated assuming a sound velocity of 1500 m/s).本文件夹收纳了2017年2月于加利福尼亚南部近海、圣地亚哥与达纳角海域采集的单频道啁啾脉冲（CHIRP）浅地层剖面数据，本次调查以圣地亚哥海槽断层为研究对象，作业平台为"Sally Ride"号科考船。 数据集包含以下内容：经处理的SEG-Y数据、WGS-84坐标系导航文件以及测线绘图文件。 本项目的核心CHIRP调查航次于2017年2月3日至11日开展，搭载"Sally Ride"号科考船，由Ian Lawrence船长指挥，属于取芯试航航次。首席科学家Mitch Lyle慷慨应允，允许我们在取芯作业间隙通宵开展地震剖面测量工作。 本次调查由来自斯克里普斯海洋研究所（SIO）的Hector Perea与Neal Driscoll负责现场实施，Bormann（内华达大学里诺分校/加州州立大学长滩分校，UNR/CSULB）则在岸上远程规划并监控数据采集流程。 本次调查共获取32条全新浅地层剖面，总测线长度达280千米，属于超高分辨率浅地层剖面数据（见图2——品红色网格）。 数据采集采用安装于船壳的Knudsen Chirp 3260回声测深仪，工作频率为3.5千赫。作业航速介于4.0至5.5节之间，信号发射间隔为3秒。反射波形以0.06毫秒的采样间隔进行采集，采样窗口时长为0.267秒，并可自动追踪海底界面。 信号可穿透海底下方0.6至1秒的双向旅行时区间，对沉积物上部45至70米深度范围内的反射界面进行成像；所有浅地层深度及地层厚度均假设声速为1500米/秒进行估算。