TY - JOUR

T1 - Magma plumbing system and seismicity of an active mid-ocean ridge volcano

AU - Schmid, Florian

AU - Schlindwein, Vera

AU - Koulakov, Ivan

AU - Plötz, Aline

AU - Scholz, John Robert

N1 - Publisher Copyright: © 2017 The Author(s).

PY - 2017/2/20

Y1 - 2017/2/20

N2 - At mid-ocean ridges volcanism generally decreases with spreading rate but surprisingly massive volcanic centres occur at the slowest spreading ridges. These volcanoes can host unexpectedly strong earthquakes and vigorous, explosive submarine eruptions. Our understanding of the geodynamic processes forming these volcanic centres is still incomplete due to a lack of geophysical data and the difficulty to capture their rare phases of magmatic activity. We present a local earthquake tomographic image of the magma plumbing system beneath the Segment 8 volcano at the ultraslow-spreading Southwest Indian Ridge. The tomography shows a confined domain of partial melt under the volcano. We infer that from there melt is horizontally transported to a neighbouring ridge segment at 35 km distance where microearthquake swarms and intrusion tremor occur that suggest ongoing magmatic activity. Teleseismic earthquakes around the Segment 8 volcano, prior to our study, indicate that the current magmatic spreading episode may already have lasted over a decade and hence its temporal extent greatly exceeds the frequent short-lived spreading episodes at faster opening mid-ocean ridges.

AB - At mid-ocean ridges volcanism generally decreases with spreading rate but surprisingly massive volcanic centres occur at the slowest spreading ridges. These volcanoes can host unexpectedly strong earthquakes and vigorous, explosive submarine eruptions. Our understanding of the geodynamic processes forming these volcanic centres is still incomplete due to a lack of geophysical data and the difficulty to capture their rare phases of magmatic activity. We present a local earthquake tomographic image of the magma plumbing system beneath the Segment 8 volcano at the ultraslow-spreading Southwest Indian Ridge. The tomography shows a confined domain of partial melt under the volcano. We infer that from there melt is horizontally transported to a neighbouring ridge segment at 35 km distance where microearthquake swarms and intrusion tremor occur that suggest ongoing magmatic activity. Teleseismic earthquakes around the Segment 8 volcano, prior to our study, indicate that the current magmatic spreading episode may already have lasted over a decade and hence its temporal extent greatly exceeds the frequent short-lived spreading episodes at faster opening mid-ocean ridges.

KW - CONSTRAINTS

KW - DE-FUCA RIDGE

KW - DYNAMICS

KW - EVENT

KW - EXPLOSIVE VOLCANISM

KW - OCEAN-RIDGE

KW - SEGMENT

KW - SOUTHWEST INDIAN RIDGE

KW - THICKNESS

UR - http://www.scopus.com/inward/record.url?scp=85013436894&partnerID=8YFLogxK

U2 - 10.1038/srep42949

DO - 10.1038/srep42949

M3 - Article

C2 - 28218270

AN - SCOPUS:85013436894

VL - 7

SP - 42949

JO - Scientific Reports

JF - Scientific Reports

SN - 2045-2322

M1 - 42949

ER -