TY - JOUR

T1 - Structure of volatile conduits beneath gorely volcano (Kamchatka) revealed by local earthquake tomography

AU - Kuznetsov, Pavel Y.

AU - Koulakov, Ivan

AU - Jakovlev, Andrey

AU - Abkadyrov, Ilyas

AU - Deev, Evgeny

AU - Gordeev, Evgeny I.

AU - Senyukov, Sergey

AU - El Khrepy, Sami

AU - Al Arifi, Nassir

PY - 2017/12/1

Y1 - 2017/12/1

N2 - Gorely is an active volcano located 75 km from Petropavlovsk-Kamchatsky, Kamchatka. In 2010-2015, it exhibited strong activity expressed by anomalously high gas emission. In 2013-2014, we deployed a temporary network consisting of 20 temporary seismic stations that operated for one year. We selected 333 events with 1613 P-wave and 2421 S-wave arrival times to build the first tomographic model of this volcano. The seismic model was carefully verified using a series of synthetic tests. Our tomographic model provides a mechanism for volatile feeding of Gorely. An unexpected feature of the model was low Vp/Vs ratios, below 1.4 in some parts. One reason for such low Vp/Vs ratios is gas contamination due to magma degassing. In the central part of the model, directly underneath the Gorely crater, we observe a 2.5 km wide and 1.5 km thick seismic anomaly with a very high Vp/Vs ratio of up to 2. This may represent a magma reservoir with a high melt and/or volatile content. The upper limit of this anomaly, 2.5 km below the surface, may indicate the degassing level, which coincides with the most intense seismicity. Below this reservoir, we observe another columnar high Vp/Vs ratio anomaly. This can be interpreted as a conduit bringing magma and fluids from deeper sources.

AB - Gorely is an active volcano located 75 km from Petropavlovsk-Kamchatsky, Kamchatka. In 2010-2015, it exhibited strong activity expressed by anomalously high gas emission. In 2013-2014, we deployed a temporary network consisting of 20 temporary seismic stations that operated for one year. We selected 333 events with 1613 P-wave and 2421 S-wave arrival times to build the first tomographic model of this volcano. The seismic model was carefully verified using a series of synthetic tests. Our tomographic model provides a mechanism for volatile feeding of Gorely. An unexpected feature of the model was low Vp/Vs ratios, below 1.4 in some parts. One reason for such low Vp/Vs ratios is gas contamination due to magma degassing. In the central part of the model, directly underneath the Gorely crater, we observe a 2.5 km wide and 1.5 km thick seismic anomaly with a very high Vp/Vs ratio of up to 2. This may represent a magma reservoir with a high melt and/or volatile content. The upper limit of this anomaly, 2.5 km below the surface, may indicate the degassing level, which coincides with the most intense seismicity. Below this reservoir, we observe another columnar high Vp/Vs ratio anomaly. This can be interpreted as a conduit bringing magma and fluids from deeper sources.

KW - Degassing

KW - Gas contamination

KW - Gorely volcano

KW - Magma reservoir

KW - Travel-time tomography

KW - degassing

KW - SEISMIC VELOCITY STRUCTURE

KW - FIELD

KW - magma reservoir

KW - INVERSION

KW - travel-time tomography

KW - gas contamination

KW - REGION

KW - ERUPTION

KW - KLYUCHEVSKOY

KW - ACTIVE VOLCANOS

UR - http://www.scopus.com/inward/record.url?scp=85035347352&partnerID=8YFLogxK

U2 - 10.3390/geosciences7040111

DO - 10.3390/geosciences7040111

M3 - Article

AN - SCOPUS:85035347352

VL - 7

JO - Geosciences (Switzerland)

JF - Geosciences (Switzerland)

SN - 2076-3263

IS - 4

M1 - 111

ER -