FN Archimer Export Format
PT J
TI Nonseismic Signals in the Ocean: Indicators of Deep Sea and Seafloor Processes on Ocean‐Bottom Seismometer Data
BT 
AF Batsi, Evangelia
   Tsang‐Hin‐Sun, Eve
   Klingelhoefer, Frauke
   Bayrakci, Gaye
   Chang, Emmy T.Y.
   Lin, Jing‐Yi
   Dellong, David
   Monteil, Clément
   Géli, Louis
AS 1:1;2:1;3:1;4:2;5:3;6:4,5;7:1;8:1;9:1;
FF 1:PDG-REM-GM-LAD;2:;3:PDG-REM-GM-LAD;4:;5:;6:;7:PDG-REM-GM-LAD;8:;9:PDG-REM-GM-LAD;
C1 Ifremer, Marine Geosciences CS Plouzané, France
   University of Southampton, Ocean and Earth Science, National Oceanography Centre Southampton Southampton, UK
   Institute of Oceanography, National Taiwan University Taipei ,Taiwan
   Department of Earth SciencesNational Central University Taoyuan City ,Taiwan
   Center for Environmental Studies, National Central University Taoyuan City ,Taiwan
C2 IFREMER, FRANCE
   UNIV SOUTHAMPTON, UK
   UNIV NATL TAIWAN NTU, TAIWAN
   UNIV NATL CTRL, TAIWAN
   UNIV NATL CTRL, TAIWAN
SI BREST
SE PDG-REM-GM-LAD
IN WOS Ifremer UPR
   copubli-europe
   copubli-int-hors-europe
IF 2.623
TC 8
UR https://archimer.ifremer.fr/doc/00507/61895/65983.pdf
   https://archimer.ifremer.fr/doc/00507/61895/65984.pdf
LA English
DT Article
DE ;marine seismology;gas and fluid migration;Sea of Marmara;Chilean subduction
AB Ocean bottom seismometers (OBS) commonly record short duration events (SDEs), that could be described by all of these characteristics: (i) duration < 1 s, (ii) one single‐wave train with no identified P‐ nor S‐wave arrivals and (iii) a dominant frequency usually between 4 Hz and 30 Hz. In many areas, SDEs have been associated with gas or fluid‐related processes near cold seeps or hydrothermal vents, although fish bumps, instrumental or current‐generated noise have been proposed as possible sources. In order to address some remaining issues, this study presents results from in situ and laboratory experiments combined with observations from 2 contrasting areas, the Sea of Marmara (Turkey) and the Chilean subduction zone. The in situ experiment was conducted at the EMSO‐Molène submarine observatory (near Brest, France) and consisted in continuously monitoring two OBSs with a camera. The images revealed that no fish regularly bumped into the instruments. Laboratory experiments aimed at reproducing SDEs’ waveforms by injecting air or water in a tank filled by sand and sea‐water and monitored with an OBS. Injecting air in the sediments produced waveforms very similar to the observed SDEs, while injecting air in the water column did not, constraining the source of SDEs in the seafloor sediments. Finally, the systematic analysis of two real data sets revealed that it is possible to discriminate gas‐related SDEs from biological or sea‐state related noise from simple source parameters, such as the temporal mode of occurrence, the back azimuth and the dominant frequency. Key Points Short duration high amplitude events routinely recorded on marine seismometers are not created by fish bumping into the geophone. In laboratory experiments, the waveforms of these events are well reproduced by fluid migration in the sediments. We propose 3 simple source parameters to discriminate gas‐related short duration events in ocean bottom seismometer data. 
PY 2019
PD AUG
SO Geochemistry Geophysics Geosystems
SN 1525-2027
PU American Geophysical Union (AGU)
VL 20
IS 8
UT 000490955300005
BP 3882
EP 3900
DI 10.1029/2019GC008349
ID 61895
ER

EF