“Visions in Ice”

The glittering blue interior of an ice cave sparkles in this award-winning image by photographer Yasmin Namini. The cave is underneath Iceland’s Vatnajokull Glacier. Notice the deep scallops carved into the lower wall. This shape is common in melting and dissolution processes. It is unavoidable for flat surfaces exposed to a melting/dissolving flow. (Image credit: Y. Namini/WNPA; via Colossal)

For more insight into the tectonic background of today’s M7.7 #earthquake in Myanmar I’d recommend this blog post and the original article on extrusion tectonics. There is also a video hiding somewhere on YouTube that illustrates this experiment perfectly.
#myanmar #geology #geoscience #tectonics #geophysics
https://blogs.egu.eu/divisions/ts/2021/02/15/ts-must-read-tapponnier-et-al-1982-propagating-extrusion-tectonics-in-asia/

Slipping Ice Streams

The Northeast Greenland Ice Stream provides about 12% of the island’s annual ice discharge, and so far, models cannot accurately capture just how quickly the ice moves. Researchers deployed a fiber-optic cable into a borehole and set explosive charges on the ice to capture images of its interior through seismology. But in the process, they measured seismic events that didn’t correspond to the team’s charges.

Instead, the researchers identified the signals as small, cascading icequakes that were undetectable from the surface. The quakes were signs of ice locally sticking and slipping — a failure mode that current models don’t capture. Moreover, the team was able to isolate each event to distinct layers of the ice, all of which corresponded to ice strata affected by volcanic ash (note the dark streak in the ice core image above). Whenever a volcanic eruption spread ash on the ice, it created a weaker layer. Even after hundreds more meters of ice have formed atop these weaker layers, the ice still breaks first in those layers, which may account for the ice stream’s higher-than-predicted flow. (Image credit: L. Warzecha/LWimages; research credit: A. Fichtner et al.; via Eos)

Salt Affects Particle Spreading

Microplastics are proliferating in our oceans (and everywhere else). This video takes a look at how salt and salinity gradients could affect the way plastics move. The researchers begin with a liquid bath sandwiched between a bed of magnets and electrodes. Using Lorentz forcing, they create an essentially 2D flow field that is ordered or chaotic, depending on the magnets’ configuration. Although it’s driven very differently, the flow field resembles the way the upper layer of the ocean moves and mixes.

The researchers then introduce colloids (particles that act as an analog for microplastics) and a bit of salt. Depending on the salinity gradient in the bath, the colloids can be attracted to one another or repelled. As the team shows, the resulting spread of colloids depends strongly on these salinity conditions, suggesting that microplastics, too, could see stronger dispersion or trapping depending on salinity changes. (Video and image credit: M. Alipour et al.)

Daily report

Here are today's most popular trending hashtags on our website ️:

#cosmos, #science, #wonder, #space, #linuxgaming, #gaming, #geophysics, #ubuntu, #steam, #astrophotography, #unix

Stay tuned!

Flooding the Mediterranean

Nearly 6 million years ago, the Mediterranean was cut off from the ocean and evaporated faster than rivers could replenish it. This created a salty desert that persisted until about 5.3 million years ago. One hypothesis — the Zanclean megaflood — suggests that the Mediterranean refilled rapidly through an erosion channel near the Strait of Gilbraltar. A new study bolsters the concept by identifying geological features near Sicily consistent with the megaflood.

The team point to a grouping of over 300 ridges near the Sicily Sill, once a land bridge dividing the eastern and western Mediterranean and now underwater. The ridges are layered in debris but aren’t streamlined, suggesting they were rapidly deposited by turbulent waters, and date to the period of the proposed flooding. For more on the Zanclean Flood, check out this older post. (Image credit: R. Klavins; research credit: A. Micallif et al.; via Gizmodo)

Job - Alert

PHD POSITION (F_M_X) – EVALUATION OF SEDIMENTARY THERMAL ROCK PROPERTIES

Deadline: 2025-03-30

Location: Germany, Potsdam, Brandenburg

https://www.academiceurope.com/job/?id=7036

[First results from #DORN on the #Moon] The recovery of samples of #regolith and lunar rocks, coupled with the analysis of #surface gases by the #DORN instrument, has enabled the scientists involved in the #ChangE6 mission to identify the occurrence of two volcanic episodes on the far side of the Moon, 4.2 and 2.8 billion years ago. For the record, the samples brought back by the #Apollo and #Luna missions from the visible side of our satellite attest to a single volcanic event, dating back more than 3 billion years.

Further analyses are underway, which will “refine previous observations made by remote sensing, which have shown that the far side of the Moon is different, in terms of #geophysics (differences in crustal thickness, for example) and the chemical and mineralogical composition of the rocks, from that of the visible side”, explains Pierre-Yves Meslin, astronomer at IRAP.

Info+ : https://www.polytechnique-insights.com/tribunes/espace/la-face-cachee-de-la-lune-les-premiers-echantillons-arrivent-sur-terre/

Grfin Tools—User Guide And Methods For Modeling Landslide Runout And Debris-Flow Growth And Inundation
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https://pubs.usgs.gov/publication/tm14A3 <-- shared USGS publication
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https://code.usgs.gov/grfintools/grfintools <-- shared USGS software release
--
H/T Jonathan Perkins USGS
[ another open source resource for everyone from the USGS ~smile~ ]
#GIS #spatial #mapping #opensource #openlibrary #Grfin #software #package #regional #debrisflow #engineeringgeology #geology #inundation #spatialanalysis #spatiotemporal #geophysics #geophysical #massmovement #landslide #lahar #volcano #rock #avalanche #model #modeling #statistical #geostatistics #water #hydrology #downstream #elevation #remotesensing #DEM #flow #runout #risk #hazard #tools #slope #erosion #drainage #network #channel #channelisation #userguide
@USGS

Danish seismologist and geophysicist Inge Lehmann died #OTD in 1993.

She is best known for her discovery in 1936 of the solid inner core that exists within the molten outer core of the Earth. The seismic discontinuity in the speed of seismic waves at depths between 190 and 250 km is named the Lehmann discontinuity after her. Lehmann is considered to be a pioneer among women and scientists in seismology research.

https://en.wikipedia.org/wiki/Inge_Lehmann

Job Alert

RESEARCH ASSISTANT (M/F/D) FIELD OF CIVIL ENGINEERING, PHYSICS, GEOPHYSICS, ELECTRICAL ENGINEEERING

Deadline: 2025-03-02

Location: Germany, Berlin, Steglitz

https://www.academiceurope.com/job/?id=6946

Predicting Landslide Speeds

Knowing what speed a landslide will reach helps us predict how much damage they can cause. That speed depends on many factors: the steepness of the terrain, the sliding distance, the thickness of the flowing layer, and the type of grains making up the flow. Researchers found that predictions from previous studies often underestimated the speeds reached by thicker flows. Through laboratory experiments with grains of different shapes, a team found that those models mistakenly assumed a fully-developed flow — in other words, one where the grains have reached a constant final speed. While spherical grains reach that state over a short sliding distance, that’s not the case for other grains.

Instead, the team used their results to build a new predictive model for landslide speeds. This one still depends on incline angle and flow thickness, but it also uses a dynamical friction coefficient to describe the granular material and capture how the flow’s speed varies with distance down the incline. (Image credit: W. Hasselmann; research credit: Y. Wu et al.; via APS News)

How Did The Great Lakes Form? Scientists Think They Figured It Out
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https://www.earth.com/news/how-did-the-great-lakes-form-surprising-new-clues-have-emerged/#google_vignette <-- shared technical link
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https://doi.org/10.1029/2024GL110777 <-- shared paper
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#geology #mapping #structuralgeology #USA #Canada #GreatLakes #NorthAmerica #CapeVerde #hotspot #tectonics #magma #Superior #Michigan #Huron #Erie #Ontario #freshwater #lake #mantle #formation #pangaea #supercontinent #remotesensing #geophysics #continent #kimberlites #seismicvelocitymodel #model #modeling #plume #lithosphere #glacial #glacier #anisotropy

Today is the International Day of Women and Girls in Science. Let’s put those in the research fields of the @ORB_KSB in the spotlight.
https://www.astro.oma.be/en/international-day-of-women-and-girls-in-science%e2%80%89-%e2%80%89women-researchers-in-astronomy-and-geophysics/
#WomenInScience #WomenInSTEM #Astronomy #Geophysics #WomenInAstronomy

My PR has been merged into the IAGA International Geomagnetic Reference Field (IGRF) ppigrf repository. The changes provide users with greater control over the spherical harmonics expansion by allowing them to specify the minimum and maximum degree of the expansion.

The animation shows the multipole contributions to Earth's global magnetic field displayed as field magnitude. This illustrates the complexity of the geomagnetic field.

https://github.com/IAGA-VMOD/ppigrf/pull/21

Another connection between the Earth and space environments: terrestrial lighting.

"One of the ways to disturb electrons in the inner radiation belt and kick them into Earth’s atmosphere actually begins in the atmosphere itself."

https://theconversation.com/lightning-strikes-link-weather-on-earth-and-weather-in-space-243772

GSPy - A New Toolbox And Data Standard For Geophysical Datasets
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https://doi.org/10.3389/feart.2022.907614 <-- shared paper
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https://doi.org/10.5066/P9XNQVGQ | https://code.usgs.gov/g3sc/gspy <-- shared code repository
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[an older paper, but code is in active and ongoing development/evolution]
#GIS #spatial #mapping #geophysics #geophysical #NetCDF #datatypes #code #opensource #library #dataformats #standardisation #standardization #openstandard #portable #metadata #Python #package #GSPy #methods #workflows #xarray #CRS #opendata #architecture #toolbox

'Impossible' Earthquake Challenges Everything We Knew About Earth's Interior, StudyFinds

https://studyfinds.org/impossible-earthquake-challenges-everything-we-knew-about-earths-interior/

Scientists have solved the mystery of how earthquakes can occur 420 miles deep inside Earth, where extreme pressure and heat should make rock flow rather than break. The key is a mineral called olivine that transforms under pressure, creating conditions for earthquakes at impossible depths.