Imperial College London
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ProfessorMikeWarner

Faculty of Engineering, Department of Earth Science & Engineering

Professor
 
 
 
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Contact

 

+44 (0)20 7594 6535m.warner

 
 
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Assistant

 

Ms Daphne Salazar +44 (0)20 7594 7401

 
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Location

 

RSM 1.46CRoyal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Hooft:2019:10.1016/j.epsl.2019.02.033,
author = {Hooft, EEE and Heath, BA and Toomey, DR and Paulatto, M and Papazachos, CB and Nomikou, P and Morgan, JV and Warner, MR},
doi = {10.1016/j.epsl.2019.02.033},
journal = {Earth and Planetary Science Letters},
pages = {48--61},
title = {Seismic imaging of Santorini: subsurface constraints on caldera collapse and present-day magma recharge},
url = {http://dx.doi.org/10.1016/j.epsl.2019.02.033},
volume = {514},
year = {2019}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Volcanic calderas are surface depressions formed by roof collapse following evacuation of magma from an underlying reservoir. The mechanisms of caldera formation are debated and predict differences in the evolution of the caldera floor and distinct styles of magma recharge. Here we use a dense, active source, seismic tomography study to reveal the sub-surface physical properties of the Santorini caldera in order to understand caldera formation. We find a ∼3-km-wide, cylindrical low-velocity anomaly in the upper 3 km beneath the north-central portion of the caldera, that lies directly above the pressure source of the 2011-2012 inflation. We interpret this anomaly as a low-density volume caused by excess porosities of between 4% and 28%, with pore spaces filled with hot seawater. Vents that were formed during the first three phases of the 3.6 ka Late Bronze Age (LBA) eruption are located close to the edge of the imaged structure. The correlation between older volcanic vents and the low-velocity anomaly suggests that this feature may be long-lived. We infer that collapse of a limited area of the caldera floor resulted in a high-porosity, low-density cylindrical volume, which formed by either chaotic collapse along reverse faults, wholesale subsidence and infilling with tuffs and ignimbrites, phreatomagmatic fracturing, or a combination of these processes. Phase 4 eruptive vents are located along the margins of the topographic caldera and the velocity structure indicates that coherent down-drop of the wider topographic caldera followed the more limited collapse in the northern caldera. This progressive collapse sequence is consistent with models for multi-stage formation of nested calderas along conjugate reverse and normal faults. The upper crustal density differences inferred from the seismic velocity model predict differences in subsurface gravitational loading that correlate with the location of 2011-2012 edifice inflation. This result supports the hypothesis th
AU  - Hooft,EEE
AU  - Heath,BA
AU  - Toomey,DR
AU  - Paulatto,M
AU  - Papazachos,CB
AU  - Nomikou,P
AU  - Morgan,JV
AU  - Warner,MR
DO  - 10.1016/j.epsl.2019.02.033
EP  - 61
PY  - 2019///
SN  - 0012-821X
SP  - 48
TI  - Seismic imaging of Santorini: subsurface constraints on caldera collapse and present-day magma recharge
T2  - Earth and Planetary Science Letters
UR  - http://dx.doi.org/10.1016/j.epsl.2019.02.033
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000466054900005&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - https://www.sciencedirect.com/science/article/pii/S0012821X19301360
UR  - http://hdl.handle.net/10044/1/83913
VL  - 514
ER  -
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