#megathrust — Public Fediverse posts

Satellite Captures The First Detailed Look At A Massive Tsunami
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https://www.earth.com/news/satellite-captures-the-first-detailed-look-at-a-giant-tsunami/ <-- shared technical article
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https://doi.org/10.1785/0320250037 <-- shared paper
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#GIS #spatial #mapping #satellite #remotesensing #earthobservation #geology #tectonics #Kuril #Kamchatka #Russia #Pacific #tsunami #NASA #SWOT #energy #dissipation #risk #hazard #model #modeling #DART #buoy #observation #instrumentation #waveforms #propogation #geodetic #spatialanalysis #spatiotemporal #marine #wave #megathrust #rupture #mechanics #altimetry #forecasting #hydrodynamic

We drilled deep under the sea to learn more about mega-earthquakes and tsunamis
#Earthquakes #Tsunami #Japan #JapanTrench #Chikyu #EarthquakeResearch #TsunamiScience #IODP405 #SeafloorDrilling #MegaThrust #Geoscience #TectonicPlates #DisasterPreparedness
https://the-14.com/we-drilled-deep-under-the-sea-to-learn-more-about-mega-earthquakes-and-tsunamis/

Sleeping giants may awaken after the Krasheninnikov eruption. EVEN MORE VOLCANOES ARE POPPING! #Kamchatka​ #Megathrust​ #Earthquake​ #Tsunami​ #Kresheninnkov​ #GEOPHYSICS

Megaquake triggered 7 Volcanoe...

Seismic study reveals hidden #megathrust #earthquake risk off #BritishColumbia

by Francesco Fiondella, Earth Institute at Columbia University
July 21, 2025

"A new study published in Science Advances has revealed the first detailed images of a newly developing #SubductionZone off the coast of British Columbia's Haida Gwaii archipelago.

"The international team of researchers collected the data for this study during a 2021 cruise by the Lamont-Doherty Earth Observatory's research vessel, the Marcus G. Langseth. They used a 15-kilometer-long underwater cable equipped with thousands of underwater microphones, called hydrophones, in the area off northern British Columbia to map the deep structure of Earth's subsurface.

"Their data confirmed that the #QueenCharlotteFaultSystem can generate powerful megathrust earthquakes, which are capable of producing strong shaking and #tsunamis.

"Megathrusts are found in areas where one tectonic plate dives beneath another, in this case the Pacific plate being pushed under the North American plate. This area is known for generating powerful tremors. In fact, the Queen Charlotte fault system represents the greatest seismic hazard in Canada, producing the country's largest recorded earthquake in 1949 and a notable earthquake in 2012 that created a tsunami.

" 'This region is actively becoming a subduction zone, so understanding the fault structure here tells us about the early stages of subduction zone development,' says lead author Collin Brandl, a postdoctoral research scientist at the Lamont-Doherty Earth Observatory, part of the Columbia Climate School.

" 'Our study provides the first direct observations of the Haida Gwaii thrust, the 'megathrust' of this system, which can help improve hazard analysis in the region, better preparing residents for future earthquakes and tsunamis.' "

Source:
https://phys.org/news/2025-07-seismic-reveals-hidden-megathrust-earthquake.html

Randomness Of Megathrust Earthquakes Implied By Rapid Stress Recovery After The Japan Earthquake
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https://doi.org/10.1038/ngeo2343 <-- shared (2015) paper
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#GIS #spatial #mapping #model #modeling #earthquake #japan #subduction #subductionzone #geology #risk #hazard #engineeringgeology #structuralgeology #subsurface #3dmodel #spatialanalysis #spatiotemporal #megathrust #japanese #Tohoku #Tohoku2011 #tectonics #platetectonics #plates #stress #stressrelease #rupture #quake

The Difference Between Alarming And Catastrophic - Cascadia Megafault Has One Especially Deadly Section, New Map Reveals
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https://www.livescience.com/planet-earth/geology/the-difference-between-alarming-and-catastrophic-cascadia-megafault-has-1-especially-deadly-section-new-map-reveals <-- shared technical article
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https://news.climate.columbia.edu/2024/06/08/cascadia-subduction-zone-one-of-earths-top-hazards-comes-into-sharper-focus/ <-- shared technical statement
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https://doi.org/10.1126/sciadv.adl3198 <-- shared paper
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#GIS #spatial #mapping #engineeringgeology #risk #hazard #megathrust #fault #faulting #earthquake #PNW #PacificNorthwest #CascadiaSubductionZone #remotesensing #naturalhazard #mitigation #model #modeling #geophysics #seismology #tsunami #displacement #buildingcodes #engineering #construction #warningsystems #plates #platetectonics #spatialanalysis #geometry

Cascadia Subduction Zone, One Of Earth's Top Hazards, Comes Into Sharper Focus
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https://phys.org/news/2024-06-cascadia-subduction-zone-earth-hazards.html <-- shared technical article
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https://doi.org/10.1126/sciadv.adl3198 <-- shared paper
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#GIS #spatial #mapping #PNW #USA #PacificNorthwest #BritishColumbia #Washington #Oregon #NoCal #Seattle #BC #CascadiaSubductionZone #CSZ #megathrust #earthquake #earthquakes #fault #faulting #risk #hazard #geology #structuralgeology #engineeringgeology #remotesensing #survey #geophysics #tsunami #buildingcodes #warningsystems #coast #coastal #tectonics #plates #model #modeling

Large-Scale Submarine Landslides In The Barberton Greenstone Belt, Southern Africa—Evidence For Subduction And Great Earthquakes In The Paleoarchean
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https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G51997.1/635654/Large-scale-submarine-landslides-in-the-Barberton <-- shared paper (PDF only)
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#GIS #spatial #mapping #structuralgeology #SouthAfrica #NewZealand #tectonics #subduction #BarbertonGreenstoneBelt #geologicmapping #geology #earthquakes #paleoarchean #stratigraphy #marine #sedimentation #submarinelandslide #hikurangi #megathrust #superposition

Shallow Slow Slip Events Identified Offshore The Osa Peninsula In Southern Costa Rica From GNSS Time Series [geologic faults / tectonics]
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https://doi.org/10.1029/2023GL104771 <-- shared paper
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#GIS #spatial #mapping #GPS #survey #GNSS #costarica #earthquake #faults #faulting #tectonics #shallowslowslipevent #SSE #shallowslowslip #slowslip #geodetic #spatialanalysis #spatiotemporal #osa #OsaPeninsula #station #platetectonics #geology #megathrust #MiddleAmericanTrench #centralamerica #platemotion #model #modeling

Abgetauchte Vulkane lösen Erdbeben-Rätsel. Riesiges Wasserreservoir in subduziertem Vulkanplateau vor Neuseeland entdeckt. #Geologie #Neuseeland #Vulkane #Erdbeben #Megathrust #Subduktion
https://www.scinexx.de/news/geowissen/abgetauchte-vulkane-loesen-erdbeben-raetsel/

Geoscientists Discover Massive Undersea Water Reservoir Off New Zealand’s Coast
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https://www.sci.news/othersciences/geophysics/hikurangi-water-reservoir-12323.html <-- shared technical article
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https://doi.org/10.1126/sciadv.adh0150 <-- shared paper
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#GIS #spatial #mapping #remotesensing #geology #structuralgeology #NewZealand #model #modeling #megathrust #fault #faulting #subduction #water #groundwater #Hikurangi #hydrogeology #igneous #vulcanism #volcaniclastic #seamounts #marine #bathymetry #seafloor #volcanicplateau #subductionzone #seismicimaging #seismic #earthquake #slowslip #tectonics #geoscience

@dustcircle

"Warm liquid spewing from #Oregon seafloor comes from #CascadiaFault, could offer clues to #earthquake hazards

"...hence increases the friction between the oceanic and #continental #plates.

“The #megathrust fault zone is like an air hockey table,” ...“If the fluid pressure is high, it’s like the air is turned on, meaning there’s less friction and the two #plates..."

https://www.washington.edu/news/2023/04/10/warm-liquid-spewing-from-oregon-seafloor-comes-from-cascadia-fault-could-offer-clues-to-earthquake-hazards/

Work at the #PebbleHill #reservoir began in the fall of 2021 to prepare for #NaturalDisasters in the future.
Metro #Vancouver has been steadily #upgrading its reservoirs since the '90s to ensure it can provide #water to the region following the "#BigOne " — a #megathrust #earthquake expected to hit the #BCcoast someday.
https://www.cbc.ca/amp/1.6783105

#BritishColumbia #Canada #PNW #PacificNorthwest #EarthquakeProofing #PlanningAhead #Cascadia #YVR

I am totally astounded by what I read when I compare these two texts: Maria Graham's description of the coastal #uplift due to the 1822 #Valparaiso #earthquake, versus Charles Darwin's text on very similar phenomena related to the 1835 #Concepción earthquake.

Read carefully, paying attention to the expressions used. It's like if #Darwin borrowed Maria Graham's words, but also her interpretation about the accumulation of earthquakes raising the coast on the long term. 🤔
Any comment ?

Both 1822 and 1835 earthquakes happened in Central #Chile on the #subduction #megathrust between Nazca and South America #tectonic_plates. Darwin's description, based on Fitz Roy (Beagle's captain) observations, is considered as seminal.

Thanks @haq for pointing me to the work by Maria Graham.

This recalls that even in contexts like #Java or #Sumatra, where the #subduction #megathrust may produce very big #earthquakes, much smaller shallow crustal ruptures may present significant hazards because closer to towns.
2/2

A magnitude Mw6.9 #earthquake offshore south-central #Sumatra.

Mechanism and location suggest rupture on the shallow part of the #subduction #megathrust close to the trench (on the very shallow dipping fault plane). However, modelled depth of ~19km, if true, seems little too deep given the closeness with the trench (USGS gives same depth and mechanism). This means that we cannot exclude a rupture on the steep fault plane within the oceanic plate.

Map with source time function from Geoscope IPGP
http://geoscope.ipgp.fr/index.php/en/catalog/earthquake-description?seis=us7000iqpn
Larger map with epicenter of this event in red from USGS (both not yet on fediverse it seems)