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Dave Petley @davepetley.bsky.social · 2h

Satellite images of the parts of #Mexico affected by heavy rainfall in recent days are being captured by @planet.com. This is the area around Conquextla, for example. There are many shallow landslides, some of which have combined to create channelised debris flows. This pattern is repeated widely.

Planet image of the area around Conquextla in Mexico, showing multiple shallow landslides.

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Dave Petley @davepetley.bsky.social · 1d

An excellent new paper in the journal Landslides (Xie et al. 2025) describes a cluster of 143 landslides that was triggered by about 140 mm of rainfall, killing two people, in Pengshui County, China on 12 July 2024.
Before and after images by @planet.com
eos.org/thelandslide...

The site of the 12 July 2024 landslides in Pengshui County, Chongqing, China. Image copyright Planet, used with permission. Image dated 24 May 2024.

The aftermath of the 12 July 2024 landslides in Pengshui County, Chongqing, China. Image copyright Planet, used with permission. Image dated 1 August 2024.

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Dave Petley @davepetley.bsky.social · 2d

Both Sheffield universities are on the inner ring road. The University of Sheffield campus is bisected by it, and the inner ring road runs between Sheffield Hallam University and the railway station.

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Dave Petley @davepetley.bsky.social · 2d

Reconstruction by Quiroga et al (2025) of landslides on the banks of Lake Rupanco in Chile, triggered by the 22 May 1960 Mw-9.5 earthquake, indicate that a 161 million m^3 landslide triggered a tsunami with a maximum amplitude of 33.3 m. About 120 people were killed.
eos.org/thelandslide...

Google Earth image of the site of the landslides on the banks of Lake Rupanco triggered by the 22 May 1960 earthquake in Chile.

Hotel Termas de Rupanco, which was destroyed by the landslide-induced tsunami 1960. Image from Enterreno. Posted by Francisco Vidal Guzmán under a by-nc licence.

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Reposted by Dave Petley

Bob Digby @bobdigby.bsky.social · 4d

Calling all A level Geography teachers! Remember the Hazards conferences where experts would present up-to-date lectures on a wide range of hazards topics? They’re back, now organised by kcmconferences.co.uk! Includes locations in London, Manchester and Nottingham. Other subjects available!

KCM Events and Conferences | Enthuse, Empower and Engage students

Our panel of expert speakers will cover the very latest developments in their ever-changing fields, deepening students’ knowledge

kcmconferences.co.uk

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Reposted by Dave Petley

Ilan Kelman @ilankelman.bsky.social · 6d

Empowering Education:
A UK hazards conference focusing on secondary school students and their teachers.
www.kcmconferences.co.uk/events/categ...
@davepetley.bsky.social @proffionatweed.bsky.social

#geography #geogteacher #geogteachers #teamgeog #geographyteacher #geographyteachers #DRR

KCM Events and Conferences

www.kcmconferences.co.uk

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Dave Petley @davepetley.bsky.social · 6d

The report of the Board of Inquiry into the 14 January 2025 McCrae Landslide in Australia found that a major burst in a water main triggered the failure. The leak, which began at least 150 days before the landslide, released at least 40 million liters of water into the slope.
eos.org/thelandslide...

Photograph showing the 14 January 2025 McCrae landslide, highlighting the house that was destroyed. Image from the Board of Inquiry report

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Dave Petley @davepetley.bsky.social · 7d

The 17 December 2024 Takhini River landslide and river-ice tsunami in Whitehorse, Yukon, Canada highlights the role of progressive failure in frozen materials.
eos.org/thelandslide...

Surface elevation change detection comparing 2013 lidar DTM to a 2025 DSM created from UAV photos for the Takhini River landslide.

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Reposted by Dave Petley

Dr Dan Shugar 🇨🇦 @watershedlab.bsky.social · 8d

New satellite imagery from @planet.com this morning shows water overflowing the Tala Hydroelectric Power Station in Bhutan. Hard to tell from this, but appears the dam hasn't failed at this point. Unclear what the brown stuff is in the lake upstream. Logs or sediment upstream landslides perhaps? 🧪⚒️

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Dave Petley @davepetley.bsky.social · 8d

Take a look at my blog post from yesterday about the landslides in Darjeeling. I address your question about development directly:-
eos.org/thelandslide...

A late monsoon sting in the tale in the Himalayas

Very heavy rainfall across Nepal, NE. India and Bhutan has triggered landslides that have killed at least 60 people.

eos.org

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Dave Petley @davepetley.bsky.social · 8d

In July 2025 I recorded 71 fatal landslides worldwide, with the loss of 214 lives. The number of fatal landslides was above the long term mean of 58.1 landslides.
eos.org/thelandslide...

The number of fatal landslides to 29 July 2025, displayed in pentads. For comparison, the long term mean (2004 to 2016) and the exceptional year of 2024 are also shown.

The number of fatal landslides to the end of July 2025 by month.

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Dave Petley @davepetley.bsky.social · 9d

Very heavy rainfall across Nepal, NE. India and Bhutan has triggered landslides that have killed at least 60 people.
eos.org/thelandslide...

A late monsoon sting in the tale in the Himalayas

Very heavy rainfall across Nepal, NE. India and Bhutan has triggered landslides that have killed at least 60 people.

eos.org

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Reposted by Dave Petley

Dr Dan Shugar 🇨🇦 @watershedlab.bsky.social · 11d

This article about mountain and cryospheric hazards, featuring quotes from @davepetley.bsky.social @matthias-huss.bsky.social @janbeutel.bsky.social and others was published a few months ago, but is still very relevant 🧪⚒️ www.cnn.com/2025/06/07/c...

Mountains are among the planet’s most beautiful places. They’re also becoming the deadliest | CNN

These majestic landscapes have always been dangerous, but as the world warms, mountains are becoming much more unpredictable — and the world is unprepared.

www.cnn.com

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Dave Petley @davepetley.bsky.social · 12d

Some excellent before and after imagery is now available showing the evolution of the Matai'an landslide dam. This image has been posted to Facebook by Tony Lee. More details on my blog:-
eos.org/thelandslide...

Before and after images of the Matai'an landslide dam. Video by Tony Lee, posted to Facebook.

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Dave Petley @davepetley.bsky.social · 13d

Good digital data is now being published by ASRS that presents the scale of landscape change that occurred as a result of the Matai'an landslide hazard cascade. There is also interesting information about the root causes of the vulnerability of the town of Guangfu.
eos.org/thelandslide...

Vertical elevation change before and after the Matai'an landslide and dam breach. Published by ASRS in Taiwan.

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Dave Petley @davepetley.bsky.social · 15d

Today is the first meeting of the Research Plus collective, a panel discussion on the role of universities in growth and the industrial strategy.

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Reposted by Dave Petley

Marc-André Brideau @mabrideau.bsky.social · 16d

Over the last three years, @drewbrayshaw.bsky.social, @geocron.bsky.social, me, and twelve colleagues have been compiling a Preliminary Canadian Landslide Database. Version 12 is now available and contains 25,500 entries.
zenodo.org/records/1721...

Overview map of Canada with location points of 25,550 landslides symbolized according to 30 landslide types. Background image is a combination of ESRI satellite imagery and hillshade of the NRCan High Resolution Digital Elevation Model (HRDEM)

Overview map of Canada with location points of 25,550 landslides symbolized according to what version of the database they were last modified. It shows that more than half they entries were added or modified in the latest version. Background image is a combination of ESRI satellite imagery and hillshade of the NRCan High Resolution Digital Elevation Model (HRDEM)

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Dave Petley @davepetley.bsky.social · 16d

For more detailed analysis of the damage in #Guangfu after #supertyphoonRagasa, see my blog post:
eos.org/thelandslide...
#Ragasa #landslide

The aftermath of the Matai'an landslide in Taiwan

It is likely that the final death toll from the collapse of the Matai'an landslide dam will be 25 people, with over 100 injured.

eos.org

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Dave Petley @davepetley.bsky.social · 16d

Satellite images from @planet.com show the level of damage in Guangfu in the aftermath of the breach of the Matai'an landslide dam in Taiwan in typhoon #Ragasa. It is clear that a very large part of the community suffered inundation. In total, 18 people were killed and seven are still missing.

A satellite image of Guangfu township in Taiwan before the breach of the Matai'an landslide dam. Image copyright Planet, used with permission. Image dated 30 August 2025.

A satellite image of Guangfu township in Taiwan after the breach of the Matai'an landslide dam. Image copyright Planet, used with permission. Image dated 27 September 2025.

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Dave Petley @davepetley.bsky.social · 20d

At least 15 people are known to have been killed by the debris flow and flood from the landslide dam breach that was triggered by typhoon Ragasa. Reports suggest that 15.4 million tonnes of water were released, causing 80 metres of downcutting of the landslide dam.
eos.org/thelandslide...

The aftermath of the landslide dam breach at Matai'an in Taiwan. Image by the Forest Protection Department.

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Reposted by Dave Petley

Kristen Cook @kristencook.bsky.social · 21d

The Matai’an landslide dam in eastern Taiwan has failed this afternoon (eos.org/thelandslide...), flooding Guangfu, about 15 km downstream focustaiwan.tw/society/2025.... Even in the middle of a typhoon, the resulting flood produced a detectable seismic signal at stations ~40 km away.

Seismic waveforms and power spectral density plots showing the signal of a landslide lake outburst flood.

Planet satellite image from August 2025 of a large landslide blocking a river and creating a lake.

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Dave Petley @davepetley.bsky.social · 21d

The Matai'an landslide dam breach in Taiwan during super typhoon Ragasa is now known to have killed 14 people. Some reports indicate a substantial number may still be missing (one source suggests 124 people). Understandably, the situation is quite unclear at the moment.
#supertyphoonRagasa #Ragasa

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Dave Petley @davepetley.bsky.social · 22d

Yes, they provide two versions (Panel 1 and Panel 2). Same data, different scales. CWA recommends Panel 2 when precipitation >400 mm.
The availability of two panels was, I believe, a recommendation after Typhoon Morakot.

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Dave Petley @davepetley.bsky.social · 22d

Overtopping and downcutting, probably, although it is not entirely clear.

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Dave Petley @davepetley.bsky.social · 22d

Taipei News reports that there have been two likely fatalities and 75 people are trapped.
www.taipeitimes.com/News/taiwan/...

Two missing, 75 trapped as floodwaters overflow lake - Taipei Times

Bringing Taiwan to the World and the World to Taiwan

www.taipeitimes.com

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