Publication Date:
2019-03-05
Description:
The seismic and volcanological structure of Deception Island (Antarctica) is an
intense focus topic in Volcano Geophysics. The interpretations given by scientists on the
origin, nature, and location of the structures buried under the island strongly diverge. We
present a high-resolution 3D P-wave attenuation tomography model obtained by using the
coda normalization method on 20,293 high-quality waveforms produced by active sources.
The checkerboard and synthetic anomaly tests guarantee the reproduction of the input
anomalies under the island down to a depth of 4 km. The results, once compared with our
current knowledge on the geological, geochemical, and geophysical structure of the region,
depict Deception as a piecemeal caldera structure coming out of the Bransfield Trough. Highattenuation
anomalies contouring the northeastern emerged caldera rim correlate with the
locations of sediments. In our interpretation, the main attenuation contrast, which appears
under the collapsed southeastern caldera rim, is related to the deeper feeding systems. A unique P-wave high-attenuation spherical-like anomaly in the inner bay extends between
depths of 1 and 3 km. The northern contour of the anomaly coincides with the calderic rim
both at 1 and 2 km, while smaller anomalies connect it with deeper structures below 3 km,
dipping toward the Bransfield Trough. In our interpretation, the large upper anomaly is caused
by a high-temperature shallow (1–3 km deep) geothermal system, located beneath the
sediment-filled bay in the collapsed blocks and heated by smaller, deeper contributions of
molten materials (magma) rising from southeast.
Description:
Published
Description:
371–390
Description:
4T. Fisica dei terremoti e scenari cosismici
Description:
1V. Storia e struttura dei sistemi vulcanici
Description:
JCR Journal
Description:
restricted
Keywords:
Attenuation
;
Scattering
;
Tomography
;
Antarctica
;
04. Solid Earth::04.06. Seismology::04.06.07. Tomography and anisotropy
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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