TY - JOUR

T1 - Fault-Associated Magma Conduits Beneath Volcán de Colima Revealed by Seismic Velocity and Attenuation Tomography Studies

AU - Sychev, Ilya V.

AU - Koulakov, Ivan

AU - Egorushkin, Igor

AU - Zhuravlev, Sergey

AU - West, Michael

AU - El Khrepy, Sami

AU - Al-Arifi, Nasir

AU - Alajmi, Mamdoh S.

N1 - Publisher Copyright: © 2019. American Geophysical Union. All Rights Reserved.

PY - 2019/8/1

Y1 - 2019/8/1

N2 - We present the results of tomographic studies using seismic velocity and attenuation in the area of the Colima Volcanic complex (CVC). Our dataset comprises body waves from local earthquakes recorded by the temporary seismic stations of the CODEX network in the Colima area and a few stations of the regional Mapping the Rivera Subduction Zone (MARS) networks, both deployed in 2006–2008. We obtain three-dimensional distributions of seismic velocities and attenuation in the crust beneath the CVC area. At shallow depths, we observe a large negative anomaly to the south of CVC, coinciding with the location of the Central Colima Graben. This anomaly may represent debris avalanche deposits, as well as shallow magma reservoirs feeding the eruptions of the presently active Volcán de Colima. In contrast, the volcano edifice of Nevado de Colima, which is built of rigid igneous rocks, is associated with high-velocity and low-attenuation anomalies at shallow depths. In the deeper section, a major anomaly with high Vp/Vs, low Vs, and high S wave attenuation corresponds to the location of the regional Tamazula fault. As this represents a mechanically weakened zone of the crust, it may form the pathway that feeds CVC. Both velocity and attenuation models show that the fault-associated conduit brought magma from the mantle through the lower crust to a depth of 15 km. Then, a light fraction of magma may continue to ascend, forming shallow reservoirs beneath the southern flank of CVC.

AB - We present the results of tomographic studies using seismic velocity and attenuation in the area of the Colima Volcanic complex (CVC). Our dataset comprises body waves from local earthquakes recorded by the temporary seismic stations of the CODEX network in the Colima area and a few stations of the regional Mapping the Rivera Subduction Zone (MARS) networks, both deployed in 2006–2008. We obtain three-dimensional distributions of seismic velocities and attenuation in the crust beneath the CVC area. At shallow depths, we observe a large negative anomaly to the south of CVC, coinciding with the location of the Central Colima Graben. This anomaly may represent debris avalanche deposits, as well as shallow magma reservoirs feeding the eruptions of the presently active Volcán de Colima. In contrast, the volcano edifice of Nevado de Colima, which is built of rigid igneous rocks, is associated with high-velocity and low-attenuation anomalies at shallow depths. In the deeper section, a major anomaly with high Vp/Vs, low Vs, and high S wave attenuation corresponds to the location of the regional Tamazula fault. As this represents a mechanically weakened zone of the crust, it may form the pathway that feeds CVC. Both velocity and attenuation models show that the fault-associated conduit brought magma from the mantle through the lower crust to a depth of 15 km. Then, a light fraction of magma may continue to ascend, forming shallow reservoirs beneath the southern flank of CVC.

KW - Colima Volcanic complex

KW - magma plumbing system

KW - P and S wave velocities

KW - seismic attenuation

KW - seismic tomography

KW - Volcán de Colima

UR - http://www.scopus.com/inward/record.url?scp=85070947548&partnerID=8YFLogxK

U2 - 10.1029/2019JB017449

DO - 10.1029/2019JB017449

M3 - Article

AN - SCOPUS:85070947548

VL - 124

SP - 8908

EP - 8923

JO - Journal of Geophysical Research: Solid Earth

JF - Journal of Geophysical Research: Solid Earth

SN - 2169-9313

IS - 8

ER -