FN Archimer Export Format
PT J
TI Improved detection and Coulomb stress computations for gas-related, shallow seismicity, in the Western Sea of Marmara
BT 
AF Tary, Jean-Baptiste
   Géli, Louis
   Lomax, Anthony
   Batsi, Evangelia
   Riboulot, Vincent
   Henry, Pierre
AS 1:1;2:2;3:3;4:2;5:2;6:4;
FF 1:;2:PDG-REM-GM-LAD;3:;4:PDG-REM-GM-LAD;5:PDG-REM-GM-LAD;6:;
C1 Departamento de Geociencias, Universidad de los Andes, Bogotá, Colombia
   Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Marine Geosciences Research Unit, BP 70, 29280 Plouzané, France
   ALomax Scientific, 320 Chemin des Indes, 06370, Mouans Sartoux, France
   Aix Marseille University, CNRS, IRD, INRA, Collège de France, CEREGE, Aix-en-Provence, France
C2 UNIV LOS ANDES, COLOMBIA
   IFREMER, FRANCE
   ALOMAX SCIENTIFIC, FRANCE
   UNIV AIX MARSEILLE, FRANCE
SI BREST
SE PDG-REM-GM-LAD
IN WOS Ifremer UPR
   copubli-france
   copubli-univ-france
   copubli-int-hors-europe
   copubli-sud
IF 4.823
TC 3
UR https://archimer.ifremer.fr/doc/00484/59522/62605.pdf
LA English
DT Article
DE ;shallow seismicity;triggering;stress transfer;North Anatolian Fault;Sea of Marmara
AB The Sea of Marmara (SoM) is a marine portion of the North Anatolian Fault (NAF) and a portion of this fault that did not break during its 20th century earthquake sequence. The NAF in the SoM is characterized by both significant seismic activity and widespread fluid manifestations. These fluids have both shallow and deep origins in different parts of the SoM and are often associated with the trace of the NAF which seems to act as a conduit. On July 25th, 2011, a 5 strike-slip earthquake occurred at a depth of about 11.5 km, triggering clusters of seismicity mostly located at depths shallower than 5 km, from less than a few minutes up to more than 6 days after the mainshock. To investigate the triggering of these clusters we first employ a match filter algorithm to increase the number of event located and hence better identify potential spatio-temporal patterns. This leads to a 2-fold increase in number of events relocated, coming mostly from the shallow seismic clusters. The newly detected events confirm that most of the aftershocks are shallow, with a large number of events located in the first few km below the SoM seafloor. Pore pressure diffusion from the position of the deep mainshock to the position of the shallow events is incompatible with the short time interval observed between them. We therefore investigate static and dynamic stress triggering processes. The shallow clusters fall into either positive or negative lobes with static stress variations of about ±5 kPa. Dynamic stresses may reach values of about ±40 kPa depending on the rise time and the fault orientation considered, but cannot last longer than the perturbations associated with the seismic waves from the mainshock. We then propose a mechanism of fluid pressure increase involving local fluid transfers driven by the transient opening of gas-filled fractures due to earthquake shaking, to explain the triggering of the shallow events of the clusters. 
PY 2019
PD MAY
SO Earth And Planetary Science Letters
SN 0012-821X
PU Elsevier BV
VL 513
UT 000463307800012
BP 113
EP 123
DI 10.1016/j.epsl.2019.02.021
ID 59522
ER

EF