Anthony Lomax @ALomax@qoto.org
#Earthquake happenings+tidbits, maps, #MachineLearning... I'm ALomax Scientific: earthquake monitoring and analysis.
"seismicity is only the edges and shadows of complex, 3D space-time tectonic processes"
Car free for daily life since 1976.
Joined Nov 2022
We would like to thank the editors at @weareseismica and the reviewers for a very agreeable and smooth (no pun intended) submission, review and copy-production process. Highly recommended!
We use NLL-SSST-coherence (https://doi.org/10.1029/2021JB023190) an enhanced, absolute-timing earthquake location procedure which uses 1) spatially-varying station time corrections to improve multi-scale precision and 2) waveform similarity to improve fine-scale precision.
Multi-scale smooth, planar or arcuate faults slip without geometric impediment, which likely influences earthquake initiation, rupture, rupture direction, and arrest. Extensive, smooth fault segments may even be necessary for large earthquake to occur.
@weareseismica While we image the Parkfield segment of the San Andreas Fault as a planar surface at seismogenic depth, we find the Central/Southern Calaveras fault is an arcuate surface which follows closely the circumference of a circle.
Now out in @weareseismica, our paper "Major California faults are smooth across multiple scales at seismogenic depth" https://seismica.library.mcgill.ca/article/view/324
Our relocated seismicity images faults at seismogenic depth as smooth, planar or arcuate surfaces across the sub-km to 10’s of km scales.
NLL-SSST-coherence (https://doi.org/10.1029/2021JB023190) is an enhanced, absolute-timing earthquake location procedure which uses 1) spatially-varying station time corrections to improve multi-scale precision and 2) waveform similarity to improve fine-scale precision.
Earthquake arrival time data from NCEDC https://ncedc.org
Velocity model (KS) from https://doi.org/10.1785/0220140121, https://eartharxiv.org/repository/view/1904
Faults from https://sciencebase.gov/catalog/item/589097b1e4b072a7ac0cae23
Only hypocenters with location error ≤ 5km are plotted.
Map views of the relocated seismicity 2000-present with NCSS 2013 Mw5.7 fault plane (violet) from https://earthquake.usgs.gov/earthquakes/eventpage/nc71996906/moment-tensor
NCSS 2023 Mw5.5 fault plane (yellow) from https://earthquake.usgs.gov/earthquakes/eventpage/nc73886731/moment-tensor
Quick seismo-tectonic interpretation of high-precision relocations of the Mw5.5 2023-05-11 Lake Almanor, CA earthquake sequence and background seismicity since 2000: Normal-faulting 2023 mainshock rupture towards the NW; oblique, normal + strike-slip splay and 2013 faulting to the SE.
The NCSS 2013 Mw5.7 fault plane matches the tabular spread of most 2013 aftershocks (violet). The Mw5.7 event has oblique, right-lateral + extensional faulting.
The relocated seismicity and fault planes show non-coplanar but adjoining 2013 and 2023 faulting.
Anthony Lomax
boosted
Using remote sensing data, Barbot et al. analyze the rupture of the Türkiye 2023 Kahramanmaraş earthquake sequence.
They highlight a segment of the East Anatolian fault that has not been broken yet, and could generate another Mw 6.8 earthquake.
read more: https://doi.org/10.26443/seismica.v2i3.502
#Seismology #EarthquakeScience #DiamondOpenAccess #Earthquake #Türkiye #OpenAccess #OpenScience #earthquake
Apr 18, 1906 San Francisco earthquake: Sparse timing data (including quick reading of wall clocks by local observers!) are sufficient to estimate the hypocenter location within about 10-20km (red cloud) - the epicenter is quite near San Francisco. https://pubs.geoscienceworld.org/ssa/bssa/article/95/3/861/103179/A-Reanalysis-of-the-Hypocentral-Location-and
Apr 18, 1906 San Francisco earthquake: my work on the likely hypocenter location & complex ruptures in the focal region https://pubs.geoscienceworld.org/ssa/bssa/article/98/2/846/350139/Location-of-the-Focus-and-Tectonics-of-the-Focal
The 1906 M7.8 California earthquake occurred 117 years ago: 1906-04-18 13h12mUTC. Here is recent seismicity (1984-2022) west of San Francisco. The 1906 hypocenter was likely in the yellow box, perhaps within the deep, linear trend of recent earthquakes (yellow).
Anthony Lomax
boosted
You have a jar full of very smelly perfume. The easiest way to keep your room not smelling of perfume is:
(a) don't spill the perfume
(b) splash it everywhere and then invent a "putting perfume back in the jar machine."
Good. Now, you have a planetary crust full of a dangerous warming substance. The easiest way to keep your planet hospitable is....
Anthony Lomax
boosted
Take a look at our abstract word cloud! Our publications are already speaking volumes - what topics have we covered so far?
Check them out, PDF or XML format:
https://seismica.org/issue/view/16
#seismology #earthquakescience #peerreviewed #openaccess #diamondopenaccess #scientificjournal
NLL-SSST-coherence (https://doi.org/10.1029/2021JB023190) is an enhanced, absolute-timing earthquake location procedure which 1) iteratively generates spatially varying travel-time corrections to improve multi-scale precision and 2) uses waveform similarity to improve fine-scale precision.
Image shows 16,762 events 2020-01-01 to 2023-03-04 with err ≤ 9km
Cyan: before 2023-01-01; includes 2020 Mw6.8 Elazığ, Turkey sequence
Green-Yellow: before 2023-02-06 M7.8 event
Red: from 2023-02-06 01h17 UTC M7.8 through 10h24 UTC M7.6
Magenta: after 2023-02-06 10h24 UTC M 7.6
Precise, NLL-SSST-coherence earthquake relocations for the 2023 Mw7.8 and Mw7.6, Kahramanmaraş-Gaziantep, Turkey earthquake sequence (including 2020 Mw 6.8 Elazığ, Turkey sequence). Seismic arrival data from https://afad.gov.tr. Details & catalog available at: https://doi.org/10.5281/zenodo.7699881
Anthony Lomax
boosted
Seismica is announcing a special journal issue on the 2023 Kahramanmaras, Türkiye earthquake sequence, with papers free-to-publish and free-to-read.
https://seismica.org/issue/view/28
#DiamondOpenAccess #seismology #EarthquakeScience
#earthquake
Anthony Lomax
boosted
However long Jimmy Carter has left now that he has entered hospice, it has been such a gift that the best person to hold the office, certainly in the 20th century and possibly ever, is also the longest lived. What a life. What a better country and world we would be if we had more like him.
Anthony Lomax
boosted
A meter-wide asteroid (only the 7th object detected in space before reaching Earth) just disintegrated harmless over the English Channel. #Sar2667
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RT @BNODesk
WATCH: Meteor lights up the sky in northern France
https://twitter.com/BNODesk/status/1624968247035428864
#Earthquake happenings+tidbits, maps, #MachineLearning... I'm ALomax Scientific: earthquake monitoring and analysis.
"seismicity is only the edges and shadows of complex, 3D space-time tectonic processes"
Car free for daily life since 1976.
Joined Nov 2022
