The University of Southampton
University of Southampton Institutional Repository
Warning ePrints Soton is experiencing an issue with some file downloads not being available. We are working hard to fix this. Please bear with us.

Complex and cascading triggering of submarine landslides and turbidity currents at volcanic islands revealed from integration of high-resolution onshore and offshore surveys

Complex and cascading triggering of submarine landslides and turbidity currents at volcanic islands revealed from integration of high-resolution onshore and offshore surveys
Complex and cascading triggering of submarine landslides and turbidity currents at volcanic islands revealed from integration of high-resolution onshore and offshore surveys
Submerged flanks of volcanic islands are prone to hazards including submarine landslides that may trigger damaging tsunamis and sediment-laden seafloor flows (called “turbidity currents”). These hazards can break seafloor infrastructure which is critical for global communications and energy transmission. Small Island Developing States are particularly vulnerable to these hazards due to their remote and isolated nature, small size, high population densities, and weak economies. Despite their vulnerability, few detailed offshore surveys exist for such islands, resulting in a geohazard “blindspot,” particularly in the South Pacific. Understanding how these hazards are triggered is important; however, pin-pointing specific triggers is challenging as most studies have been unable to link continuously between onshore and offshore environments, and focus primarily on large-scale eruptions with sudden production of massive volumes of sediment. We address these issues by integrating the first detailed (2 × 2 m) bathymetry data acquired from Tanna Island, Vanuatu with a combination of terrestrial remote sensing data, onshore and offshore sediment sampling, and documented historical events. Mount Yasur on Tanna has experienced low-magnitude Strombolian activity for at least the last 600 years. We find clear evidence for submarine landslides and turbidity currents, yet none of the identified triggers are related to major volcanic eruptions, in contrast to conclusions from several previous studies. Instead we find that cascades of non-volcanic events (including outburst floods with discharges of >1,000 m3/s, and tropical cyclones), that may be separated by decades, are more important for preconditioning and triggering of landslides and turbidity currents in oversupplied sedimentary regimes such as at Tanna. We conclude with a general model for how submarine landslides and turbidity currents are triggered at volcanic and other heavily eroding mountainous islands. Our model highlights the often-ignored importance of outburst floods, non-linear responses to land-use and climatic changes, and the complex interactions between a range of coastal and tectonic processes that may overshadow volcanic regimes.
Clare, Michael A.
b26da858-9c08-4784-aaa9-7092efcd94bd
Le Bas, Tim
5880f375-bbf2-4f20-8618-7f344aa76f7f
Price, David M.
c41cad17-a645-4682-9299-59065d41eabe
Hunt, James E.
2e95b3c8-734f-4ade-8010-8ed32fe4fe5e
Sear, David
ccd892ab-a93d-4073-a11c-b8bca42ecfd3
Cartigny, Matthieu J. B.
bda1b79b-7e11-4790-8238-b86d80a88bb3
Vellinga, Age
9957dfd4-70a8-4327-b66c-af7f718a0e75
Symons, William
57c58604-e967-4cba-8ab3-fd690c1f5635
Firth, Christopher
7e209304-6290-4035-b93a-3d9e4ce323f9
Cronin, Shane
d4a630a0-985e-4c79-b25d-96100ec801bf
Clare, Michael A.
b26da858-9c08-4784-aaa9-7092efcd94bd
Le Bas, Tim
5880f375-bbf2-4f20-8618-7f344aa76f7f
Price, David M.
c41cad17-a645-4682-9299-59065d41eabe
Hunt, James E.
2e95b3c8-734f-4ade-8010-8ed32fe4fe5e
Sear, David
ccd892ab-a93d-4073-a11c-b8bca42ecfd3
Cartigny, Matthieu J. B.
bda1b79b-7e11-4790-8238-b86d80a88bb3
Vellinga, Age
9957dfd4-70a8-4327-b66c-af7f718a0e75
Symons, William
57c58604-e967-4cba-8ab3-fd690c1f5635
Firth, Christopher
7e209304-6290-4035-b93a-3d9e4ce323f9
Cronin, Shane
d4a630a0-985e-4c79-b25d-96100ec801bf

Clare, Michael A., Le Bas, Tim, Price, David M., Hunt, James E., Sear, David, Cartigny, Matthieu J. B., Vellinga, Age, Symons, William, Firth, Christopher and Cronin, Shane (2018) Complex and cascading triggering of submarine landslides and turbidity currents at volcanic islands revealed from integration of high-resolution onshore and offshore surveys. Frontiers in Earth Science, 6, [223]. (doi:10.3389/feart.2018.00223).

Record type: Article

Abstract

Submerged flanks of volcanic islands are prone to hazards including submarine landslides that may trigger damaging tsunamis and sediment-laden seafloor flows (called “turbidity currents”). These hazards can break seafloor infrastructure which is critical for global communications and energy transmission. Small Island Developing States are particularly vulnerable to these hazards due to their remote and isolated nature, small size, high population densities, and weak economies. Despite their vulnerability, few detailed offshore surveys exist for such islands, resulting in a geohazard “blindspot,” particularly in the South Pacific. Understanding how these hazards are triggered is important; however, pin-pointing specific triggers is challenging as most studies have been unable to link continuously between onshore and offshore environments, and focus primarily on large-scale eruptions with sudden production of massive volumes of sediment. We address these issues by integrating the first detailed (2 × 2 m) bathymetry data acquired from Tanna Island, Vanuatu with a combination of terrestrial remote sensing data, onshore and offshore sediment sampling, and documented historical events. Mount Yasur on Tanna has experienced low-magnitude Strombolian activity for at least the last 600 years. We find clear evidence for submarine landslides and turbidity currents, yet none of the identified triggers are related to major volcanic eruptions, in contrast to conclusions from several previous studies. Instead we find that cascades of non-volcanic events (including outburst floods with discharges of >1,000 m3/s, and tropical cyclones), that may be separated by decades, are more important for preconditioning and triggering of landslides and turbidity currents in oversupplied sedimentary regimes such as at Tanna. We conclude with a general model for how submarine landslides and turbidity currents are triggered at volcanic and other heavily eroding mountainous islands. Our model highlights the often-ignored importance of outburst floods, non-linear responses to land-use and climatic changes, and the complex interactions between a range of coastal and tectonic processes that may overshadow volcanic regimes.

Text
feart-06-00223 - Version of Record
Available under License Creative Commons Attribution.
Download (19MB)

More information

Accepted/In Press date: 21 November 2018
Published date: 13 December 2018

Identifiers

Local EPrints ID: 429565
URI: http://eprints.soton.ac.uk/id/eprint/429565
PURE UUID: bcd69264-f596-4a55-94ef-c4764554d513
ORCID for David Sear: ORCID iD orcid.org/0000-0003-0191-6179

Catalogue record

Date deposited: 29 Mar 2019 17:30
Last modified: 22 Nov 2021 02:37

Export record

Altmetrics

Contributors

Author: Michael A. Clare
Author: Tim Le Bas
Author: David M. Price
Author: James E. Hunt
Author: David Sear ORCID iD
Author: Matthieu J. B. Cartigny
Author: Age Vellinga
Author: William Symons
Author: Christopher Firth
Author: Shane Cronin

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×