******************************************************************************************************* Seafloor acoustic ranging data across the North-Anatolian Fault, Marmara Sea, Turkey CSV FILES with acoustic rangings from November 2014 to January 2018 Created in November 2015 by Helen Piete (LGO) Last updated: March 2019 by J-Y Royer (LGO) Inquiries: Jean-Yves Royer CNRS-UBO-IUEM Geosciences Ocean Rue Dumont d'Urville, F-29280 Plouzane https://www-iuem.univ-brest.fr/lgo/ jean-yves.royer@univ-brest.fr ******************************************************************************************************* ....................................................................................................... INSTRUMENT ID , location and available records ....................................................................................................... ID Latitude Longitude Depth Start End 2001 40.8707 N 28.5187 E 811m Oct. 29, 2014 Jan. 19, 2018 14h07 2002 40.8682 N 28.5236 E 804m Oct. 29, 2014 Jan. 19, 2018 12h10 2003 40.8681 N 28.5133 E 805m Oct. 29, 2014 Jan. 19, 2018 14h07 2004 40.8704 N 28.5287 E 825m Oct. 29, 2014 Apr. 19, 2015 01h02 Communication between 2004 and the surface failed after Apr 19 2015, but the transponder continued to range and reply to the other transponders. Schematic layout of the transponders: 2001 -------------------------- 2004 / \ / / \ / / \ / / \ / 2003 ------------------------ 2002 Baseline approximate lengthes: 2001-2002 506m 2001-2003 545m 2001-2004 847m 2002-2003 870m 2002-2004 499m 2003-2004 were too far appart to communicate ....................................................................................................... INSTRUMENT CONFIGURATION ....................................................................................................... Acoustic transponders are Sonardyne Fetch-AMT. The acoustic ranging signal uses a medium-frequency (22.5 kHz), phase-coded 8ms-long pulse. Observations are time stamped by a precision clock with a 1 µs accuracy, and a drift < 3 ppm in 10 years. Each instrument is equipped with ancillary sensors: - Sensor #1 = Valeport MiniSVS 100 mm temperature and soundspeed sensor - Sensor #2 = Paroscientific Digiquartz 42K-101 pressure sensor - Sensor #3 = Jewell Instruments LSRP90 Inclinometers Transponders are programmed to perform multiple, redundant, high frequency measurements in a slave/master mode, based on the following sequence: every hour, the first unit wakes up as "master", performs measurements with each of its additional sensors, and interrogates simultaneously the three other units of the array. The solicited "slave" transponders subsequently answer with an identical signal, and simultaneously measure the temperature and sound speed in seawater 5 minutes later, the second unit becomes "master" 10 minutes later, the third unit becomes "master" 15 minutes later, the last unit becomes "master" a whole session lasts a little less than 20 minutes Note: transponder 2001 could range transponders 2002, 2003 and 2004 transponder 2002 could range transponders 2001, 2003 and 2004 transponder 2003 could range transponders 2001 and 2002 transponder 2004 could range transponders 2001 and 2002 Data logging summary : ----------------------------------------------------------------- Session interval 1h Wake-up interval as Master 5 min Number of samples / session ----------------------------------------------------------------- Ranges 3 at 5s interval Sound-speed 10 (1 as Master + 3*3 as Slave) Temperature 10 (1 as Master + 3*3 as Slave) Pressure 1 Number of samples / day ----------------------------------------------------------------- Attitude (pitch & roll) 1 every 24h (every 24 sessions) Battery voltage 1 every 24h (every 24 sessions) Number of ranging per baseline (i.e. two-way-travel times) ----------------------------------------------------------------- Per session 6 Per day 144 ....................................................................................................... CSV FILE CONTENT ....................................................................................................... Each CSV file contains data from one transponder. Each data thread is introduced by a code indicating the data type: PAG = Page number (i.e. internal sub-file number) SVT = Sound speed and temperature data TIM = Time stamp BSL = Ranging data (from the transponder to the 3 other transponders) PRS = Pressure data INC = Inclinometer data BAT = Battery SNS, SLG, BAS = instrument and signal status The file header describes the content of data threads: PAG Record Time Retrieval Time Node ID Page Number SVT Record Time Retrieval Time Node ID SoundSpeed (m/s) Temperature (deg C) TIM Record Time Retrieval Time Node ID BSL Record Time Retrieval Time Node ID Range Node Range Address Range (ms) PRS Record Time Retrieval Time Node ID Pressure (kPa) Temperature (deg C) INC Record Time Retrieval Time Node ID Pitch (Rads) Roll(Rads) SLG Record Time Retrieval Time Node ID Start Logging Log Interval Jitter SNS Record Time Retrieval Time Node ID Sensor Number Main Log Count SecondaryLogCount BAS Record Time Retrieval Time Node ID Combined CIS and WktCIS RX Wait Baseline 1 BAT Record Time Retrieval Time Node ID Used Percentage (%) Volts (V)