Geobulletin alpha

Field Photos: Boudinage In Sandstone 

Boudinage is a structure that is developed when rock layers are being pulled and stretched. The term is derived from the French word for sausage. A rock layer is deformed by necking and is segmented into a string of sausages. The structure is best developed when there is contrast in competence or strength in a rock pile. The stronger layer is broken up in boudins, while the weaker layer

Field Photos: Folds- Tectonic Or Soft Sediment Deformation? 

During my wandering in the high valleys of Kumaon I have been noticing some intriguing boulders of sandstone which have rolled down from the high ridges in the vicinity of Panchachuli Glacier and Milam Glacier. I have access to only these blocks and for now have not been able to observe them in outcrop. But they do show some spectacular deformation as seen in the picture below.Is this folding

Geology Outcrop Quiz: Milam Glacier Area 

In the outcrop below, which direction are the strata dipping (tilting)? North is to the right. If your answer was towards the right (north), you would be wrong.The apparent northward dip of the rock layers is an illusion caused by fractures intersecting the plane of the exposure. The outcrop below from a nearby spot shows the real geometry of the strata.This is an across the bedding exposure.

2023 International Summer School on Rockslides and Related Phenomena in the Kokomeren River Basin (Kyrgyzstan) (ICL Kokomeren Summer School) 

Alexander Strom and Kanatbek Abdrakhmatov will run their famous summer school again after it had to be cancelled due to Covid-19. The summer school is designed for students and will take place from 14-29 August, 2023, in Kyrgyzstan. The topics include mass movements, neotectonics, and geomorphology in the epicentral area of the M7.2 1992 Suusamyr Earthquake. Find all the details in the announcement

Tutorial by Ian Pierce: combining SfM photogrammetry with the iPad lidar for better results 

Structure-from-Motion is now a standard technique for documenting outcrops and paleoseismic trenches. It is also widely used in archaeology, architecture, disaster response, etc. In a perfect world, we would always have lots of well-known ground control points (GCPs) for our 3D models, for example by using a differential GPS. However, quite often we can’t do that because we don’t have a dGPS, because we stumbled upon an outcrop by accident, because we don’t want to carry the tripod to

Trenching season is ongoing! 

Following an un-systematic post-dinner doomscrolling I’m happy to declare May 2022 as the trenchiest month ever. Here’s some exhibits: Safety first; if cozy and comfy it’s better. The award goes to Stéphane Baize (@Stef_EQ_Geology) and their trenches along the Cévennes fault: look at the details in the photo… like “paleo” engraved in the wooden frame to prevent collapse of the trench wall. And what about the tent? 10/10 professional style. Landscape photography award The winner is [...]

Quaternary sea-level change along the coastline of Oman 

Text: Gösta Hoffmann with contributions by Michaela Falkenroth, Valeska Decker, Bastian Schneider and Christoph Grützner “The beaches in Oman are pristine.” What sounds like an introductory sentence to a tourist brochure has scientific significance. Natural conditions without anthropogenic overprint are characteristic for vast stretches along the 1700 km coastline of Oman from the Strait of Hormuz in the north to the border of Yemen in the south. This situation allows geological research [...]

Postdoc position at Oxford University: Palaeoseismology of Central Asian Earthquake Ruptures 

There is a wonderful, amazing, extraordinary postdoc position open at Oxford University: Palaeoseismology of Central Asian Earthquake Ruptures. We seek to appoint a postdoctoral research assistant to undertake investigations of large earthquakes within the interior of Asia. The post is part of a project funded by the Leverhulme Trust called EROICA. The successful candidate will work closely with Professor Richard Walker, and will join a vibrant community of active tectonics researchers in [...]

Iceland’s rootless volcanoes 

Picture a volcano, like the one you learned about in primary school. Can you see it? Is it a big rocky mountain, perhaps with a bubbling pool of lava at the top? Is it perched above a chasm of subterranean molten rock? I bet you didn’t picture this: You’d be forgiven for mistaking these small volcanoes for a scene from the Lord of the Rings, or maybe a grassy version of the surface of Mars (in fact, these kind of volcanoes do occur on Mars). These, however, are in Iceland and are called [...]

Imaggeo on Mondays: Sunset on the Giant's Causeway 

Pictured here is the Giant's Causeway - a region of basalt columns, created 50-60 million years ago during the Paleogene. The typical polygonal form of the bedrocks, a product of active volcanic processes from the past, is well underlined by the sunset’s light; that’s why I took the photo in the late evening. The separate cracks are extended by weathering over time and are filled eluvium, geological debris from the erosion. After the lava cooled, approximately 40,000 columns have since [...]

Extreme Fieldwork In The Karakoram Mountains 

This remarkable passage from Colliding Continents by Mike Searle: "After two weeks of acclimatizing on the Lobsang Spire and Cathedral granite cliffs above camp and establishing our attack camp full of supplies we were ready to go for the summit. I was keen to climb a line up through the granite cliffs in order to map out and sample a vertical profile through the granite batholith.

Imaggeo on Mondays: On the way to Tristan's penguins 

Tristan da Cunha is a remote volcanic island in the south Atlantic Ocean. In fact, it is the most remote inhabited archipelago in the world. Tristan is still volcanically active; the last time it erupted was in 1961. After the eruption, which luckily did not have any casualties, the whole population of around 260 people evacuated the island for some time, but they all returned back to the island because it was home. I took this photo while aboard the ISOLDE research cruise associated with the [...]

Imaggeo on Mondays: Small scale processes, large scale landforms 

This picture was taken in a sea cliff gully landscape at the Portuguese coast. It shows the microrelief which small scale wash and erosional processes produce in these poorly consolidated sediments. These small scale landforms could be interpreted as initial stages of larger scale gully landforms, which can be seen in the back. This highlights the importance of regarding scales and scale linkages in the geosciences. Description by Jana Eichel, as it first appeared on imaggeo.egu.eu. Imaggeo is [...]

GeoPolicy: Bridging the gap between science and decision makers – a new tool for nuclear emergencies affecting food and agriculture 

The International Atomic Energy Agency (IAEA) has developed an online system to assist in improving the response capabilities of authorities in the event of an emergency caused by natural hazards. The Decision Support System for Nuclear Emergencies Affecting Food and Agriculture (DSS4NAFA), provides a clear overview of radioactive contamination of crops and agricultural lands through improved data management and visualisation, it also assists in decision support processes by suggesting [...]

A creeping intracontinental thrust fault in the Tien Shan 

The Tien Shan takes up about 20 mm/yr of N-S shortening as a result of the India-Eurasia convergence. Recent paleoseismological studies have shown that the shortening is accommodated by a large number of faults, whose slip rates are relatively low. Although the historical earthquake catalogues only reach back a few hundred years, we know that the Tien Shan has seen some of the strongest intracontinetal quakes world-wide with magnitudes exceeding M8. Paleoseismological studies have revealed a [...]

Imaggeo on Mondays: Probing the Pliocene 

The heights we go to for science… This photograph shows a member of our team preparing to abseil down a cliff in the Charyn Canyon, in the Ili River basin of southeast Kazakhstan. The Charyn River and its tributaries, a branch of the Ili River north of the Tien Shan Mountains, have cut canyons up to 300 metres deep, carving through rocks of different geologic ages, some as old as 540 million years. The name “Charyn” may derive from local Uighur or Turkic words for “ash tree” or [...]

Large landslide in the epicentral area of the 1889 Chilik M8 Earthquake, Kazakhstan 

A large landslide occurred in SE Kazakhstan near the town of Saty (Саты), TengriNews.kz reports. The slide is about 900 m wide, 1700 m long, and has an estimated volume of ~50,000,000 m³.   Apparently nobody was harmed, but the now slow-moving landslide mass approaches Kolsai river. The road to Kolsai lake (a landslide lake) is blocked. Images and videos from the area show what may be a thick layer of loess that moved downhill after heavy rain. From

Imaggeo on Mondays: The Crossroads of Flood and Drought 

This picture was taken on the way back from collecting field measurements at the Lordsburg Playa in southwestern New Mexico, USA. The setting sun highlights the contrast between the dry, cracked soil and the standing water from antecedent rainfall. A playa is a flat topographic depression in arid or semi-arid regions that contains a large amount of deposited sediment. When the surface of the playa is dry, this deposited sediment is exposed and at risk of being entrained into the atmosphere by [...]

Imaggeo on Mondays: Winter threatens to freeze over fieldwork 

This photo was taken during a fieldwork campaign following the mainshock of the deadly seismic sequence that struck central Italy starting from 24 August 2016. The magnitude 6.2 earthquake severely damaged nearby towns, claimed more than 290 lives and injured nearly 400 people in its wake. As a geologist from the National Institute of Geophysics and Volcanology, I was in charge of measuring the manifestations of the seismic shaking (mainly fractures and landslides) on the territory. Some of the [...]

The little Thescelosaurus that could 

The Hell Creek Formation is so much more than just Triceratops and Edmontosaurus and Tyrannosaurus rex. There, I said it. I head out there to swelter and dig nearly every summer, and it's truly not the big famous dinosaurs I'm interested in. This is where Jonathan comes in. This specimen, RMDRC 06-007, was collected over a decade ago and sat in our collections partially prepared for most of that time. Coincidentally it's a specimen of Thescelosaurus neglectus, the "neglected marvelous lizard" [...]