. 24/7 Space News .
SHAKE AND BLOW
A swarm of 85,000 earthquakes at the Antarctic Orca submarine volcano
by Staff Writers
Potsdam, Germany (SPX) Apr 14, 2022

Wikipedia file image

Volcanoes can be found even off the coast of Antarctica. At the deep-sea volcano Orca, which has been inactive for a long time, a sequence of more than 85,000 earthquakes was registered in 2020, a swarm quake that reached proportions not previously observed for this region. The fact that such events can be studied and described in great detail even in such remote and therefore poorly instrumented areas is now shown by the study of an international team published in the journal "Communications Earth and Environment".

Led by Simone Cesca from the German Research Centre for Geosciences (GFZ) Potsdam, researchers from Germany, Italy, Poland and the United States were involved. With the combined application of seismological, geodetic and remote sensing techniques, they were able to determine how the rapid transfer of magma from the Earth's mantle near the crust-mantle boundary to almost the surface led to the swarm quake.

The Orca volcano between the tip of South America and Antarctica
Swarm quakes mainly occur in volcanically active regions. The movement of fluids in the Earth's crust is therefore suspected as the cause. Orca seamount is a large submarine shield volcano with a height of about 900 metres above the sea floor and a base diameter of about 11 kilometres. It is located in the Bransfield Strait, an ocean channel between the Antarctic Peninsula and the South Shetland Islands, southwest of the southern tip of Argentina.

"In the past, seismicity in this region was moderate. However, in August 2020, an intense seismic swarm began there, with more than 85,000 earthquakes within half a year. It represents the largest seismic unrest ever recorded there," reports Simone Cesca, scientist in GFZ's Section 2.1 Earthquake and Volcano Physics and lead author of the now published study. At the same time as the swarm, a lateral ground displacement of more than ten centimetres and a small uplift of about one centimetre was recorded on neighbouring King George Island.

Challenges of research in a remote area
Cesca studied these events with colleagues from the National Institute of Oceanography and Applied Geophysics - OGS and the University of Bologna (Italy), the Polish Academy of Sciences, Leibniz University Hannover, the German Aerospace Centre (DLR) and the University of Potsdam. The challenge was that there are few conventional seismological instruments in the remote area, namely only two seismic and two GNSS stations (ground stations of the Global Navigation Satellite System which measure ground displacement).

In order to reconstruct the chronology and development of the unrest and to determine its cause, the team therefore additionally analysed data from farther seismic stations and data from InSAR satellites, which use radar interferometry to measure ground displacements. An important step was the modelling of the events with a number of geophysical methods in order to interpret the data correctly.

Reconstructing the seismic events
The researchers backdated the start of the unrest to 10 August 2020 and extend the original global seismic catalog, containing only 128 earthquakes, to more than 85,000 events. The swarm peaked with two large earthquakes on 2 October (Mw 5.9) and 6 November (Mw 6.0) 2020 before subsiding. By February 2021, seismic activity had decreased significantly.

The scientists identify a magma intrusion, the migration of a larger volume of magma, as the main cause of the swarm quake, because seismic processes alone cannot explain the observed strong surface deformation on King George Island. The presence of a volumetric magma intrusion can be confirmed independently on the basis of geodetic data.

Starting from its origin, seismicity first migrated upward and then laterally: deeper, clustered earthquakes are interpreted as the response to vertical magma propagation from a reservoir in the upper mantle or at the crust-mantle boundary, while shallower, crustal earthquakes extend NE-SW triggered on top of the laterally growing magma dike, which reaches a length of about 20 kilometres.

The seismicity decreased abruptly by mid November, after about three months of sustained activity, in correspondence to the occurrence of the largest earthquakes of the series, with a magnitude Mw 6.0. The end of the swarm can be explained by the loss of pressure in the magma dike, accompanying the slip of a large fault, and could mark the timing of a seafloor eruption which, however, could not yet be confirmed by other data.

By modeling GNSS and InSAR data, the scientists estimated that the volume of the Bransfield magmatic intrusion is in the range 0.26-0.56 km. That makes this episode also the largest magmatic unrest ever geophysically monitored in Antarctica.

Simone Cesca resumes: "Our study represents a new successful investigation of a seismo-volcanic unrest at a remote location on Earth, where the combined application of seismology, geodesy and remote sensing techniques are used to understand earthquake processes and magma transport in poorly instrumented areas. This is one of the few cases where we can use geophysical tools to observe intrusion of magma from the upper mantle or crust-mantle boundary into the shallow crust - a rapid transfer of magma from the mantle to almost the surface that takes only a few days."

Research Report
Massive earthquake swarm driven by magmatic intrusion at the Bransfield Strait, Antarctica


Related Links
GFZ GeoForschungsZentrum Potsdam, Helmholtz Centre
Bringing Order To A World Of Disasters
When the Earth Quakes
A world of storm and tempest


Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


SHAKE AND BLOW
Residents survey damage after powerful Japan quake
Soma, Japan (AFP) March 17, 2022
People in northeast Japan were cleaning up and surveying the damage on Thursday after a powerful 7.4-magnitude quake derailed a bullet train, opened cracks in highways and initially cut power to over two million homes. At least one death was directly caused by the overnight quake, government spokesman Hirokazu Matsuno said, but the toll is still being finalised after two suspected fatalities were found to be unrelated to the tremor and one remains under investigation. Matsuno said 161 people had ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

SHAKE AND BLOW
Space Perspective unveils luxurious balloon-launched spaceflight experience

UCF part of historic civilian space flight to ISS

Space tourism: the arguments in favor

First private mission reaches International Space Station

SHAKE AND BLOW
Flexible quantum sieve filters out the deuterium

Rocket Lab Breaks Ground on Neutron Production Complex in Wallops, Virginia

Elon Musk urges cadet researchers to keep innovating, make rocket launches 'boring'

NASA working around valve issue to complete testing of Artemis

SHAKE AND BLOW
Sols 3442-3443: Deoch-an-Doris

Got a hitch in our giddyup - Sols 3437-3438

NASA's Curiosity Mars rover reroutes away from 'Gator-Back' rocks

Citizen scientists help map ridge networks on Mars

SHAKE AND BLOW
Shenzhou 13 astronauts ready to return

Tianzhou 2 re-enters Earth's atmosphere, mostly burns up

Shenzhou XIII astronauts prep for return

China's Tianzhou-2 cargo craft leaves space station core module

SHAKE AND BLOW
Intelsat supports programmers with cloud connect media

The race to dominate satellite internet heats up

Beyond Gravity to develop dispenser for Project Kuiper's satellite constellation

Benchmark Space Systems triples production capacity to meet thruster and in-space mobility demand

SHAKE AND BLOW
Embracing ancient materials and 21st-century challenges

Smallest earthquakes ever detected in micron-scale metals

China approves first new gaming titles in nine months

When art collectors chucked NFTs worth millions in the garbage

SHAKE AND BLOW
Diverse life forms may have evolved earlier than previously thought

A Beacon in the Galaxy: Updated Arecibo Message for Potential FAST and SETI Projects

Cosmic SETI ready to stream data for technosignature research from Jansky VLA

Prenatal protoplanet upends planet formation models

SHAKE AND BLOW
17-year Neptune study reveals surprising temperature changes

SwRI scientists connect the dots between Galilean moon, auroral emissions on Jupiter

Juice's journey and Jupiter system tour

Pluto's giant ice volcanos may have formed from multiple eruption events









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.