New images of the level of destruction in the Cusco area of Peru

The Spanish language blog El Caminerito has been covering the magnitude of the rainfall, flood and landslide disaster in Cusco, Peru. They have put together a very helpful map showing the locations of serious damage:


Ver Cusco en Emergencia en un mapa más grande

The scale of the disaster, which is still being ignored by the western media in favour of coverage of the tourists at Machu Picchu, is well-illustrated by these images of the Huacarpay region:


Meanwhile, via the Typeboard site, the Spanish language site Peru.com reports that the village of Zurite was severely damaged by a landslide, which sounds to be a debris flow (Google translation):

" the landslide of mud and stones covered the Plaza de Armas, the town’s Church, the main streets of the city and damaged 500 houses. The incident occurred about 3 pm on Thursday after they noticed a crack on a hill and began to take appropriate action, emergency services were able to evacuate the entire population."

This is the Google Earth imagery of Zurite:


There is no shortage of landslide scars on the hillside above the town, plus the quarries, one of which appears to have excavated out the toe of one of the scars.

Here is an image of the central square via the Panoramio site:

On narrow-minded press coverage

Southern Peru has for the last few days suffered extremely heavy rainfall. The Living in Peru blog reports upon the impact for local people in the province of Urubamba, Cusco. This includes
10 people killed; 2,000 collapsed houses leaving 10,000 people homeless; and crops, cattle and roads swept away. The district of Yucay is isolated due to the floods, the Vilcanota river has broken its banks on both sides, causing many local residents houses to collapse, and the police station has also been swept away.

So how does the international press report on the disaster? Like this from The Times:

Food and water dwindles as backpackers scramble to escape flood-hit Machu Picchu
British backpackers were among 1,500 tourists scrambling today to escape from Peru’s ancient Inca citadel of Machu Picchu, which has been cut off by floods and landslides since the weekend. As food supplies dwindled and hostels ran out of space, many were sleeping in the train station and the town’s main square, fighting for the few seats on rescue helicopters. “The situation is about to erupt,” Rudy Chalco, a tour guide with a group of elderly Europeans, told the Peruvian daily paper El Comercio. “We don’t have any more food, disorder is starting to reign, the soldiers and police that are here don’t know what to do or how to organise the help that has arrived, people are getting desperate and no one is taking charge.” Some tourists were prepared to pay up to $500 (£300) for a seat on one of the rescue helicopters, he said.

And so it goes on for a few more paragraphs. There is not a single mention of the plight of the local people, even though (as the article states) the authorities have declared a state of emergency.

This is the same in news reports in many other newspapers from around the world. Shameful!

Large landslides in Peru and Kyrgyzstan, the Afghanistan earthquake plus heavy rain expected in the Wenchuan area

Each year in mid-April we move into the global "landslide season", when the development of the Northern Hemisphere summer, and the associated weather patterns elsewhere, means that the number of landslides starts to increase dramatically. This is all too clear from the range of landslide events in the last few days, plus the threat of heavy rainfall in the earthquake affected areas of China:

1. Major landslide in Peru
A range of news agencies (for example AFP and CRI) are reporting that there was another large landslide in Peru, again in La Libertad Province (the second major landslide this week in that province). Although details are sketchy, this time the landslide appears to have been very large (one report suggests 1 km long), hitting two villages (Chamanacucho and Aricapampa). Reports suggest that about 30 people were killed. The coordinates of Aricapampa are (-7.80583, -77.7172), which yields the following Google Earth images:


It appears that the landslide is still active, which is hampering the recovery operation substantially.

2. Major landslide in Kyrgyzstan
According to RIAN there was also a large landslide in Kyrgyzstan yesterday. The landslide appears to have hit Raikomol village Jalalabad province in in south Kyrgyzstan, killing 16 people and a large number of cattle. All of the victims, 11 of whom are apparently children, have been recovered. The ENG24 website has posted this rather grainy, but very helpful, image of the slide:

The reports suggest that it is about 300 m long. It appears to be a massive earthflow. Unfortunately the source zone is not in the image - I would be very interested to see how and where this started.

3. The Afghanistan earthquakes
The two moderately-sized (USGS Mw=5.5 and 5.1) but shallow (USGS depth = 5.7 and 3,.2 km) earthquakes in Afghanistan this morning appear to have caused damage in at least some villages, with about 20 reported fatalities at the moment. A Google Earth image of the area affected suggests that it really is a very remote zone:

Given the remoteness of the area and the rugged terrain the number of reported fatalities might well rise during the day. Earthquakes of this size would not normally cause much damage, but the early indications are that these two events really are exceptionally shallow. I would anticipate that there will have been at least some landslides in the upland areas, but probably over quite a limited area.

4. Heavy rain forecast for the earthquake affected areas of China
Xinhua is forecasting that heavy rain will hit the areas affected by the Wenchuan earthquake over the next few days. Up to 100 mm is expected to fall. This will be the first heavy rainfall of this years rainy season. Given the amount of mobile sediment on the hillsides, and the occurrence of debris flows in heavy rainfall last September, some further problems might be expected if this heavy rainfall does occur:

Updated: Large landslide in Peru

Various Peruvian news agencies, such as Adonde.com, are carrying reports of a large rainfall-triggered landslide on Saturday night / Sunday morning in Peru. This slide, which appears to have occurred in the town of Retamas in Parcoy District of Pataz Province, has reportedly buried a number of houses, killing 13 people. The following perspective Google Earth image of the location suggests that landslides may well be a substantial problem in this area (the location is -8.0197, -77.4783 if you want to take a look for yourself):


Helpfully, the following image of Retamas is available on Panaramio at this page:


I guess it is not hard to understand how a landslide can kill 13 people in this landscape. As an aside, given that this is an area of high seismic hazard, those ridge line dwellings look very poorly located.

Update: the Latin American Herald Tribune has an article with further information here. The aricle also has an image:


The slide appears to have occurred on a steep slope above the town. The article notes that the town is “is situated on the side of a mountain and whose residents mine gold and silver...The informal mining operations in the town have affected the stability of the soil in the area", which explains the large scarps on the Google Earth image.

38 years ago today - the Chungar landslide in Peru

Today is the 38th anniversary of a notable landslide - the Chungar rock avalanche in Peru. This landslide occurred on the banks of Lake Yanahuani (sometime spelt Lake Yanahuin), about 120 km north-east of Lima (see image below):

The landslide, which had a volume of about 100,000 cubic metres, is shown on the image below. Unfortunately the Google Earth image resolution is low in this area, but you can see enough to get an idea. I have annotated the image to show the main features (click on the image for a better view):
The rockslide descended a vertical distance of about 400 m before entering the lake, whereupon it created a displacement wave that crossed the body of water at high speed. The wave struck a mining camp located on the other side of the lake, running up a vertical distance of 30 m and erasing all traces of the settlement. Between 400 and 600 people were killed. The landslide occurred on highly-fractured limestone rocks on a slope that had been over-steepened. The slope remains highly dangerous. Unfortunately the landslide is poorly documented - for example, the trigger is really not at all clear.

Landslide buries a gold mining village in Peru

Reuters is reporting that at least 10 people have been killed and a further 30 are missing after a landslide struck the gold mining village of Huanchumay, which is situated in a remote part of Carabaya province. They quote a civil defence official, Victor Ibanez, as having said:

"We have 10 dead so far and five wounded. We have no accurate data for the missing but are talking about 30 to 35 missing people. The landslide took place early on Monday morning and was due to heavy rain in the area.'

The image below shows the general location of the mine in Ayapata. This is pretty inhospitable terrain.

Earthquakes, landslide disasters and the collapse of civilisations

There is a very interesting paper being published next week in the Proceedings of the National Academy of Sciences by Dan Sandweiss, Ruth Shady, Mike Moseley, Dave Keefer and Charles Ortloff. This paper, which is reported in a long press release from the University of Florida, combines archaeology, geology and geomorphology to look at the collapse of the Supe civilisation in Peru, which survived for a couple of millennia in the coastal areas of North Peru before it appears to have abruptly collapsed and disappeared about 2000 years ago. The civilisation is intriguing because they built large and complex pyramids, some over 30 m high, as shown in the Google Earth image below. To be able to build such structures the society must have been complex and organised, so why did it disappear so abruptly?


The paper suggests that about 3,600 years ago the area was struck by a massive earthquake, an idea that is not unreasonable given that we know that this a highly seismically active area. The earthquake caused widespread destruction to the towns, but given the length of time that the civilisation survived in a seismically-active area, this would not have been the first time that this happened in all probability. The key factor was the triggering by the earthquake of massive landslides on the adjacent hills, which moved large amounts of debris into the valleys (as happened in the Wenchuan earthquake last year). This debris was then mobilised by floods triggered by heavy rainfall (again, as happened recently in Sichuan), probably associated with strong El Nino events, which bring heavy rain to this part of the world. This mobile debris would have been a hazard in itself, but more importantly it washed out to sea, whereupon it was redeposited on the coast to form a feature called the Medio Mundo, which is a large coastal bar (see below - click for a better image in a new window):

The Medio Mundo sealed off coastal bays, and thus eliminated a major source of food. Furthermore, sand from the ridge blew inland on the prevailing winds, swamping farms and communities. The huge resultant sand deposits, with the wind sculpted features, can be seen on the image above. Within a few generations the civilisation collapsed, never to recover in that form.

All-in-all a very interesting story that shows how combinations of events can lead to catastrophes. There are lessons to be learnt by modern societies from this!