DATA SET FOR: Active multiple faulting and submarine earthquake surface rupture resulting from stress transfer and seismic migration along the Liquiñe-Ofqui fault system in the Patagonian Andes

Data description: These data corresponde to high-resolution bathymetry and seismic reflection profiles obtained in the inner fjord west of Puerto Aysén (between 73.13°- 72.68°W and 45.32°-45.47°S; Figs. 1 and 2). The data set was obtained during a geophysical study as part of the DETSUFA project (Deslizamientos Tsunamigénicos en el Fiordo de Aysén; Lastras et al., 2013), which took place between March 4th  and 17th, 2013, aboard the R/V BIO Hésperides.

KONGSBERG SIMRAD multibeam EM-1002S was used to obtain bathymetric data, and it works with 111 beams at a 96 kHz sonar frequency and with a maximum ping rate of >10 Hz. Equidistant mode was used for swath bathymetry acquisition. This array maximized the number of beams facilitating data acquisition and obtaining a homogenized final grid with improved resolution, with tracks separated every 150 m. The swath thickness was the same regardless of width, generating a 50% overlap between each track, with the exception of areas located near the coast. Expendable Bathythermograph (XBT) probes were used at specific sites to measure changes in water sound velocity due to eventual changes in fresh water circulation, tides, and sediment.

Seismic reflection data were acquired using an array of two BOLT air guns (165 and 175 inches3), which were towed behind the vessel stern. The configuration used in the seismic sources was 2,000 psi, a depth of 3 m for the gun, with a firing rate of 15 m over the seafloor. A 100 m long mini-streamer with a 25 m active section, corresponding to one single channel, recovered the shots. The seismic data were recorded by using the DELPH SEISMICPLUS system with a recording length of 4.0 s and a preamplifier gain of 8 Hz. The raw seismic data were processed aboard the SMT Kingdom Suite, including the navigation and standard processes of electrical noise removing (50 Hz filter), gain amplifier and bandpass filtering, to improve data visualization.  Postprocessing  included  the  migration  of  the  sea  bottom  diffractions  and  the muting of the water column performed in Seismic-Unix.

Files:

Raw Seismic reflection data for lines 05, 06 and 07 (SU & SEG files)

Masked Seismic profiles for lines 05, 06 and 07 (SU, PDF & PS files)

Bathymetry of inner and outer Aysén Fjord (ASCII file)