Thomas R. Walter

Our review is finally out: Remote sensing of hydrothermal alteration in active volcanic environments: A critical review and integrated analysis of Lastarria volcano. Thanks to our lead author Gao, this work will provide a solid basis for volcano alteration remote sensing studies. lnkd.in/dSZiyvWt

Drone image over Kverkfjöll, Iceland, from 2 Sept 2026. The volcano is barely studied and monitored, but shows interesting hydrothermal alterations at the volcano-ice interface and occasional phreatic explosions. The blue lake is a bit warm but highly acid!

New research published in Nature Communications Earth & Environment! Our study reveals how topography-induced stress can control fissure segmentation and eruptive cone formation, using Iceland’s iconic Laki and Eldgjá eruptions as natural laboratories. www.nature.com/articles/s43...

PhD position in volcano remote sensing at GFZ Potsdam Join the ROTTnROCK ERC Synergy Project as a Doctoral Researcher investigating how volcano deformation and hydrothermal alteration shape volcanic hazards. See here www.gfz.de/en/career/jo... and check out our project here www.rottnrock.org

Our new paper is out! 🎉 We analyze post-eruption subsidence deformation at the La Palma eruption sites, providing new insights into the volcano's evolution after the 2021 eruption. Read it here: dx.doi.org/10.1029/2026...

How volcanoes affect glaciers? See our new publication, which just came out: „Decade-scale recovery of the Eyjafjallajökull ice cap, Iceland, after the 2010 summit eruption“. Congratulation to Linda, who has led this great work! link.springer.com/article/10.1...

The RottnRock team has kicked off fieldwork on Nisyros—and conditions couldn’t be better. Perfect skies and steady winds make it an ideal day for drone operations.

New paper alert: We studied the InSAR deformation field over Indonesian volcanoes and propose widely applicable processes of material movements and instability. Great work by Edgar Zorn published in Bull Volc! doi.org/10.1007/s004...

The great work by our PhD candidate Ai Lun is published: „Photogrammetry and analogue experiments in 3D-printed mold applied to the 2022-2023 lava emplacement at Lascar Volcano in Chile“. Check it out here: www.nature.com/articles/s43...

A great day at Dominica’s Boiling Lake, a hydrothermal wonder known for its bubbling surface and shifting activity, which we are closely monitoring.

Some of the ROTTnROCK team are currently in Dominica 🇩🇲 🌋 looking at, well, hydrothermal alteration of course! @magmatroll.bsky.social @trwalter.bsky.social @arianeloisel.bsky.social

Visiting Dominica. That’s the Boiling Lake, where volcanic gases superheat water to near-boiling temperatures.

Our new paper on "Volcanic Eruptions and Moss Heath Wildfires on Iceland’s Reykjanes Peninsula" is now out in GeoHazards. Website: www.mdpi.com/2624-795X/6/...

Fieldwork at Iceland’s geysers — we captured Strokkur’s eruption dynamics as polar lights lit up the sky. What a scenery! Grateful for the great collaboration with Corrado Cimarelli and the LMU team, Sasha Kostinskiy and the group from Czechia, and our team from GFZ Potsdam.

New paper alert. Volcanic crisis reveals coupled magma system at Santorini and Kolumbo. Great work led by Marius and Jens, thanks all for working on that together! It can be found in today’s issue of Nature. www.nature.com/articles/s41...

An eruption style transitional between effusive and explosive activity? Using satellite and drone-based photogrammetry and petrography we describe a strange type of block and ash flow deposits from Bezymianny volcano, Kamchatka. Check out our new paper in Bull Volc doi.org/10.1007/s004...

Huge congratulations to Claire Harnett on receiving the IAVCEI George Walker Award! 🌋 Your groundbreaking work in volcano modeling is inspiring — well deserved recognition!

100,000 orbits! The radar satellite #TerraSARX has circled Earth 100,000 times, delivering high-resolution radar data for volcanoes (and other sites of course). A milestone in space-based Earth observation leading to exciting research at #GFZ !

Big congrats to Dr. René Mania, who just defended his PhD in remote sensing at the University of Potsdam! His research focused on volcanic deformation and plumbing systems — exciting work! 🌋👏

The @rottnrock.bsky.social team arrive at Mombacho volcano 🌋 in Nicaragua 🇳🇮 to work with INETER to try to understand how alteration is influencing the volcano @rocklabstrasbourg.bsky.social @arianeloisel.bsky.social

3D scanning of alteration rock samples from volcanoes. It is part of the ERC project RottNRock!

Here it goes. Start of the LiDAR campaign at Laacher See in perfect conditions. We will create a landslide inventory at the caldera walls.

Slope instability is widespread at the caldera walls of Laacher See.

Amazing day at Laacher See caldera, Germany.

What to do when not studying volcanoes? Ice kiting. Just now. On a frozen lake near Potsdam.

Sentinel-1 dInSAR data we processed over Santorini area for the period 24 January 2025 - 05 February 2025. Fringes are mostly due to atmospheric disturbance. For the past 2 weeks, there is no major volcanic deformation visible in data.

Earthquake activity offshore Santorini, Greece, imaged in high-resolution and processed by Marius Isken in our team at GFZ using github.com/pyrocko/qseek

The 'beach ball' represents the type of slip which occurs during an earthquake. There are currently many normal fault type beach balls from earthquakes NE of Santorini island. Normal faults also escort dike intrusions, yet the true cause has to be explored still. geofon.gfz.de/eqinfo/event...

The fluctuating hydrothermal activity at Lastarria follows a systematic pattern, with changes first seen at the summit before spreading to the flanks, as our latest work shows. Check it out here: authors.elsevier.com/sd/article/S... @rottnrock.bsky.social

Glad to inform that our new paper about detecting hydrothermal deposits using the GEE platform is out. We even can identify a sulfur flow from space! Check it out here: authors.elsevier.com/sd/article/S... @rottnrock.bsky.social

InSAR data processing in the Ethiopian great rift valley is stunning, many faults and continuous deformation. Most likely related to a deflated magma chamber in the south, and a dike intrusion to the north. I will use this data in my class next week, as it is so rich in information and complexity!

A photograph from our recent Chile fieldwork, here at Lascar volcano. Drone view looking down to the multigas accumulation chamber ready to be dropped at Lascar. See the fractures degassing ? This is what we are aiming for !

Jacob Brauner just successfully defended his PhD. His works on the volcanoes of Bioko island are exciting and let us all hope for more!! Congratulations Jacob!!

Drone image at 5800m showing the crater of Lascar volcano, looking north. See the little people in the foreground? That's us.

Members of the @ROTTnROCK team on their trip to study hydrothermal alteration and volcanotectonics in Chile. See the screw in the tyre? That's tyre number 2. We need another spare! @gfz.bsky.social

That's Martin and Christian installing a multigas monitoring system at Alitar, a highly variable, hydrothermally alterating and degassing maar-like structure in Chile. @gfz.bsky.social @rottnrock.bsky.social

A view of the packed back of our pickup, with Lastarria's fumarole fields in the background. We have a generator running to charge all the batteries while we continue our survey.

Interesting sulphur structures form in the fumarole field of Lastarria volcano. Some of the tubes are almost 1 metre long and grow downwind. What would you call them?

Prelim M 5.2, Iceland #earthquake (08.12.2024 01:49:44 UTC) at 10.0 km depth. Event updates: http://geofon.gfz-potsdam.de/eqinfo/event.php?from=rss&id=gfz2024yazr

Fuck! Not again! On our volcanology tour in northern Chile.

If you have to cross a strong fumarole field by car - that's Lun, a PhD student in volcanology at the GFZ Potsdam. ⁦‪@GFZ_Potsdam‬⁩

Continuation of our drone survey over the Lastarria volcano, Chile. Perfect conditions and a lot of fun watching the amount of data grow!

At the fumaroles of Lastarria volcano, Chile. Our PhD student Gao is searching for a spot to fly the drones at close range, and for taking rock samples.

Setting up our hyperspectral drone to locate hydrothermal alterations at Lastarria volcano, Chile. ⁦‪@ROTTnROCK‬⁩

We start our field trip at Lastarria volcano, Chile.

New paper alert. Satellite Geodesy Uncovers 15 m of Slip on a Detachment Fault Prior to the 2018 Collapse at Anak Krakatau, Indonesia. dx.doi.org/10.1029/2024...

Always a pleasure to receive such emails. Wait for the paper- it’s shows loads of deformation over Krakatau volcano prior to the 2018 collapse.