Anthony Lomax @ALomax@social.cleverlibre.org

So this is my first post on Mastodon.

Part of my work as a volcanologist with the Italian National Institute of Geophysics and Volcanology (Istituto Nazionale di Geofisica e Vulcanologia, INGV) is the real-time surveillance of seismic and volcanic activity in the volcanic areas of Sicily. This is done in 8-hour shifts in the Operations Room of the INGV seat in Catania, the Osservatorio Etneo. This is me making a stupid face during my latest shift, on 5 November 2022.

Today’s #Texas M5.4 #earthquake (approximate location as a purple blob) in the context of nearby #reinjection wells and other recent #earthquakes on a map from Tung et al. (2020)

Look closely at the center of this image. You probably noticed the bright spot in the center, the central protostar. But did you notice the dark band in front of it? That’s the protostar’s accretion disk, created as material swirls around it.

The material within this disk can sometimes clump up, forming the beginnings of planets. But the protostar will absorb many of these before they can mature.

Credit: NASA, ESA, CSA, and STScI

This thread by @rvawonk digs into how central Twitter has become to relaying information during disasters, how terrible it will be to suddenly lose it.

https://twitter.com/RVAwonk/status/1592347386684506113

Yep, still angry about it.

In Europe, October 2022 was by far the warmest ever recorded, beating the previous record by over 0.5⁰C!
https://climate.copernicus.eu/surface-air-temperature-october-2022

@stevenjgibbons JMA seismic intensity maps show the greatest intensity far from the epicenter (360km deep, so Pacific Plate related). In Japanese the phenomenon of feeling a quake more strongly farther from the epicenter is called 異常震域, unusual tremor area. Do we have an English word for it?

Seismic intensity map (Japanese scale) from JMA website. M6.1, 350km depth (along the subducting Pacific Plate), not a damaging #earthquake but widely felt in Kanto and Tohoku to the North because the wave propagated efficiently along the Pacific Plate. https://www.data.jma.go.jp/multi/quake/quake_detail.html?eventID=20221114171426&lang=en

Can lots of small #earthquakes prevent a larger one from happening?

I get this question a lot and unfortunately the answer is no.

It would take 32 magnitude 5's, 1000 M4's, or 32,000 M3's to equal the energy of just one magnitude 6 event.

@freemo at well as downloading and playing with #obspy, which is highly recommended, you can see professionally produced versions of this plot, using more seismometers at #iris here: http://ds.iris.edu/spud/eventplot/20633642 and lots of further information from them here: http://ds.iris.edu/ds/nodes/dmc/tools/event/. My plot uses citizen science data collected from many private #raspishake seismometers across the globe.

Okay, there appears to be a sequence of #earthquakes in #Tonga. Here is a #map of the significant earthquakes in the area in the last 30 days. The three clusters are located > 300 km apart. Source: https://earthquake.usgs.gov/earthquakes/map/?extent=-28.70959,-187.11914&extent=-12.89718,-166.02539&range=month&magnitude=significant&sort=oldest&listOnlyShown=true&settings=true 1/N

M 6.5, Fiji Islands Region
2022-11-12 07:09:14 -20.18 -178.28 595 km A
http://geofon.gfz-potsdam.de/eqinfo/event.php?from=rss&id=gfz2022webq

Today's M7.3 #earthquake near #Tonga was a different type of event, generated by compression in the outer rise due to the bending of the #subducting slab. The shallow part of the outer rise is usually experiencing tensional #stresses and produces normal faulting quakes. The deeper section is in compression, causing reverse #faulting #earthquakes, usually with low #tsunami generating potential due to their depth.

A large M=7.3 #earthquake occurred today to the west of #Tonga islands. The #focal #mechanism shows that it involved a #thrust fault (contraction). However, its location (to the east of the trench) is somehow unusual, as the #subduction dips to west. This "outer rise" region produces earthquakes related to bending/loading of the plate, but most of them have #normal (extension) focal mechanisms. Mecanism from Geoscope/IPGP.
http://geoscope.ipgp.fr/index.php/en/catalog/earthquake-description?seis=us7000ip0l

Magnitude 7.3 #earthquake offshore Tonga 45 minutes ago (2022-11-11Z10:48) - Normal faulting. Incredible signal at station IU.CTAO (Charters Towers, Australia, available via IRIS)

https://earthquake.usgs.gov/earthquakes/eventpage/us7000ip0l/executive

See https://www.tsunami.gov/ for #tsunami information. Advisory in place

M 7.6, Tonga Islands Region
2022-11-11 10:48:44 -19.25 -172.35 15 km M
http://geofon.gfz-potsdam.de/eqinfo/event.php?from=rss&id=gfz2022wcnj