Landslides

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#1
Time for a Landslides thread, they've killed a lot more people than was previously realised.

Wake up to the death toll from killer landslides
http://www.newscientist.com/article/mg2 ... lides.html
22 October 2012 by Dave Petley

Rocks, mud and debris kill tens of thousands more people than previously realised. Time for action on this neglected global hazard

DEADLY landslides have been in the news on several occasions in recent weeks. A landslide in Yunnan, China, buried a school, killing 18 children. A series of landslides in Uttarakhand, India, claimed the lives of at least 40 people. In Dorset, UK, three people died in two landslides triggered by heavy rain.

Given these deadly impacts, it is surprising that until recently we had almost no data on the global cost of landslides, nor about where they cause the highest losses. To fill this gap, I have spent the past 10 years collecting data about deadly landslides from around the world.

The results are surprising. In a paper in the journal Geology, I analysed the data from 2004 to 2010. In this seven-year period I recorded 2620 rainfall-induced landslides worldwide that killed more than 32,000 people, a much higher toll than previously thought (vol 40, p 927).

The total number of fatalities is even higher than that, as my analysis only considered landslides triggered by rainfall. If other landslides are taken into account, especially those triggered by earthquakes, the death toll rises to a remarkable 80,000.

This is in stark contrast to official figures in the United Nations International Disaster Database, which indicate only about 7400 deaths from landslides and avalanches during the same period.

Why such a large discrepancy? The explanations lie both in what gets included and the nature of landslides themselves.

Let's address the first issue. A key factor is that the UN database includes many other hazard types, such as earthquakes, floods and volcanic eruptions. Compiling such data is a huge task, so the researchers set a minimum impact threshold for inclusion. This is either 10 fatalities or a large economic loss, meaning that many small events are excluded. This is not a problem for earthquake-related data, as unfortunately almost all events that cause significant damage also kill more than 10 people, but it leads to substantial under-reporting for landslides, most of which are small and localised.

A related issue is that the UN database records only a single cause for each death. All of the approximately 68,000 fatalities in the 2008 Sichuan Earthquake in China, for example, are recorded as resulting from the quake. In a sense this is true, but more than 20,000 people were killed by landslides triggered by the event. This is a general problem: landslides are typically triggered by another event, often intense rain or an earthquake, so their impacts are consistently underestimated.

A second key factor is that fatal landslides are concentrated in populous but remote mountain areas prone to heavy rainfall or earthquakes. The global epicentre is along the southern edge of the Himalayas; other hotspots are Indonesia, the Philippines, western China, some Caribbean islands and Colombia.

In such places, obtaining information about landslides that kill small numbers of people has been hitherto impossible. The availability of digital and social media has made it easier.

The ultimate goal of such data gathering, of course, is to reduce landslide deaths. In the past three decades several countries have set up successful programmes to manage landslide risk. A good example is Hong Kong, which suffered a series of major accidents in the 1970s. Their programme has reduced loss of life to a handful of fatalities per decade through a combination of engineering works - such as building retaining walls and installing drainage - public awareness, relocation of people most at risk and an early warning system. While replicating this in full in less developed countries is probably not feasible, some of the measures should be possible even with limited budgets.

An interesting question is whether deaths from landslides are increasing. There are good reasons to think they might be. My research shows that as population density increases so does the number of fatal landslides. In part, this is probably because rising population forces people to live and work on unstable land and, of course, when there are more people in the landscape it becomes more likely that any given landslide will hit someone.

Other factors will also be at play. Environmental degradation, especially deforestation, seems to be making landslides more likely. And the widely observed increases in rainfall intensity, which are probably associated with a warming atmosphere, may also be contributing.

My data set is still too small to determine whether there is a long-term upward trend. The impact of landslides varies considerably from year to year. Although 2010 has the highest number of recorded landslides, the number is considerably lower for 2011 and 2012 looks like it will be lower still. This probably reflects the state of global weather systems such as the El Niño/La Niña cycle, and continental systems such as the Asian monsoon, which has been much weaker than normal in 2012.

The landslide data set has very similar characteristics to a weather one; in the latter case about 30 years of data are required before a trend can be determined. It is likely that I will need to continue to compile data for 20 more years before this question can be addressed.

Rainfall-induced landslides are for the most part a manageable hazard, and a coordinated effort to reduce landslide deaths in poorer nations could be highly effective. The first step needs to be a research programme that seeks to better understand the occurrence of landslides, and the mechanisms responsible for them. Unfortunately at present there is little indication that this is a priority.

Dave Petley is a professor of geography and co-director of the Institute of Hazard, Risk and Resilience at the University of Durham in the UK
 

rynner2

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#2
This thread looks neglected (although we do have two landslip threads). But now I can offer, not one, not two, but THREE landslides!
Warning as three landslides hit coast of north Cornwall
8 April 2016

Chunks of cliff weakened by prolonged rainfall have collapsed at three separate sites.
Cornwall Council has warned of more possible landslides following the collapses along the north coast of Cornwall in the past week.

The cliff gave way near Treyarnon on Thursday with earlier cliff falls near Trevone and Morwenstow.
The South West Coast Path has been moved further inland in the affected areas.

Leroy Chandler, who runs the Trethias Farm campsite at Treyarnon, said: "There are still pieces half-way down the cliff that haven't gone all the way yet."

A Cornwall Council spokesman said the public should "be vigilant and avoid resting underneath cliffs or straying towards the seaward side of the coast path".

http://www.bbc.co.uk/news/uk-england-cornwall-35999351
 

rynner2

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#3
Another version, and some new pics:
These dramatic pictures show the scene after two major cliff falls near Padstow
By CGBen | Posted: April 08, 2016

Cormac engineers were called to Fox Cove near the Trethias Farm caravan park just before midday.
Leroy Chandler, 34, who runs the caravan park with his parents, said he heard the first fall.
"I was in the adjacent field," he told the Cornish Guardian. "I heard it go, and saw a huge cloud of dust appear in the sky.
"I'd say at least 120 tonnes of material came down".

The first sign something was wrong appeared earlier in the day, when Leroy received [a picture of cracks in the coast path] in a text message.
"The first thing I thought was 'That wasn't there yesterday'".
Leroy contacted the countryside team at Cornwall Council, who were quickly at the scene.

Leroy, who also volunteers for Padstow Coastguard, took to social media to issue a warning that people should steer clear of the area.
Meanwhile Cormac's engineers began to secure the site.
"They were quite concerned, as I was, with the cracks in the cliff path," said Leroy. "They secured it off with rope pretty quickly."


Leroy said: "While I was showing the guy from Cormac, the second part of the cliff fell.
"I've seen cliff falls in this area, but he'd never seen one actually happen before."

Leroy described the sight and sound of hundreds of tonnes of dirt and debris crumbling into the sea.
"It's like a slide," he said. "You get small amounts running off, then it starts tumbling. Then because the cliffs are at a gradient, some of it falls outwards in the same way a building would collapse.
"But because it's all fractured slates, it's not a rumbling sound. It sounds almost like tonnes of mussel shells being poured out."

As the volunteer responsible for Padstow Coastguard's Twitter account, Leroy repeated his earlier warning that people should avoid the area.

He said: "It's lucky that we're coming to the end of the Easter period now. It was a cold and wet morning and there weren't many people around".

http://www.cornishguardian.co.uk/Dr...rth-Cornwall/story-29075309-detail/story.html
 
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#4
At least 48 people have been killed in a landslide at a vast rubbish dump on the outskirts of Ethiopia's capital Addis Ababa, officials say.

They say dozens of people are still missing since the landslide on Saturday night at the Koshe landfill. A resident said 150 people were there at the time.

A number of makeshift houses are now buried under tonnes of waste.

The area has been a dumping ground for Addis Ababa's rubbish for more than five decades.

A city spokeswoman told AP news agency that many children were among the dead.

There are fears the death toll could rise further. ...

http://www.bbc.com/news/world-africa-39247381
 

gerhard1

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#5
Here is something that I thought of, and have heard concerns expressed about the potential for one occurring as a result of a landslide especially from the Canary Islands.

https://en.wikipedia.org/wiki/Megatsunami#Canary_Islands

It brings to mind the disastrous tsunami of 1700 in Japan. That resulted from an earthquake in what is now the Pacific Northwest of the USA.
 
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#6
Here is something that I thought of, and have heard concerns expressed about the potential for one occurring as a result of a landslide especially from the Canary Islands.

https://en.wikipedia.org/wiki/Megatsunami#Canary_Islands

It brings to mind the disastrous tsunami of 1700 in Japan. That resulted from an earthquake in what is now the Pacific Northwest of the USA.
I've seem a BBC programme about a possible Canary Islands Megatsunami. http://www.bbc.co.uk/science/horizon/2000/mega_tsunami.shtml

Here it is: http://documentaryheaven.com/mega-tsunami-wave-of-destruction/
 
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#7

EnolaGaia

I knew the job was dangerous when I took it ...
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#8
This new beach cliff collapse incident just north of San Diego is likely a harbinger of others that will inevitably follow ...
Collapsing California cliff claims 3 lives along beach

A popular surfing beach was closed Saturday after a cliff collapsed, sending tons of sandstone onto beachgoers and killing three people.

A 30-foot-long slab of the cliff plunged onto the sand near Grandview Beach north of San Diego. A KNSD-TV helicopter captured footage of beach chairs, towels, surf boards and beach toys strewn about the sand.

Other beachgoers and lifeguards at a nearby tower scrambled to the towering pile of debris, which was estimated to weigh tens of thousands of pounds, to help dig out victims. ...

A woman died at the scene, and two more people later died at hospitals. Another person was taken to a hospital, and a person who had minor injuries was treated at the scene, according to statements from the city. ...

Cliffside collapses are not unusual as the ocean chews away at the base of the sandstone, authorities said. Some beach areas were marked with signs warning of slide dangers.

Several people have been killed or injured over the years in bluff collapses. The Tribune reported that Rebecca Kowalczyk, 30, of Encinitas died near the same area on Jan. 16, 2000, when a 110-yard-wide chunk of bluff fell and buried her.

Bluffs give way four to eight times a year in Southern California, but “nothing of this magnitude,” said Brian Ketterer, southern field division chief of California State Parks. ...
FULL STORY: https://www.apnews.com/107bb67b289e42eb85e7c6e140f4b1c8
 
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