Featured Research

from universities, journals, and other organizations

Reconstruction of the most intense avalanches of the last 40 years in the Catalonian Pyrenees

Date:
January 13, 2010
Source:
Plataforma SINC
Summary:
Researchers have studied the dynamics of avalanches in the Catalonian Pyrenees using dendrochronology (exact dating from tree-ring growth). The results show that the periods 1971-72, 1995-96 and 2002-03 have been the most intense of the last 40 years. Avalanches in the 90s affected the entire Pyrenees and since then there have been none more intense.

Avalanche in Benasque, Pyrenean Aragonese, December 7, 2008.
Credit: Image courtesy of Plataforma SINC

Spanish researchers have studied the dynamics of avalanches in the Catalonian Pyrenees using dendrochronology (exact dating from tree-ring growth). The results show that the periods 1971-72, 1995-96 and 2002-03 have been the most intense of the last 40 years. Avalanches in the 90s affected the entire Pyrenees and since then there have been none more intense. This study helps in the prevention and mitigation of risks caused by avalanches in increasingly more urbanised areas.

Dendrochronology applied to the study of landslides has allowed scientists from the University of Barcelona (UB), and from the Geological Institute of Catalonia to date and map landslides that occurred over the 20th century, up to the present day.

The study, which has recently been published in the Natural Hazards and Earth System Sciences journal, reveals, with dendrochronological analysis and meteorological records, nine winters with avalanches during the second half of the 20th century. More severe landslides occurred in the periods 1971-72, 1995-96, and 2002-03. The study is currently ongoing in the Aragonese Pyrenees in collaboration with the University of Zaragoza.

"In a landslide area, avalanches fall which may have very different dimensions." The most frequent are usually small and do not cause damage, but some can cause damage to ground cover, infrastructure, transportation or buildings," Elena Muntán, the main author of the study and researcher at the Ecology Department of the UB, said.

The team of researchers selected six landslide areas in the Catalonian Pyrenees as a sample of the entire territory. In total, 15,000 avalanche areas have been identified in Catalonia alone.

Trees as landslide indicators

The scientists took samples of wood from living and dead trees from the landslide area to ascertain, by looking at their rings, the time at which disturbances in their growth occurred. "Snowfall causes inclination of tree trunks, damage and breakage of branches or the crown, uprooting, clearance of old or dead trees of the specimen," Muntán states.

According to the researcher, these effects are represented by identifiable ring marks, as happens with mountain pine (Pinus uncinata) in the high mountains of the Pyrenees, the inclination of which changes the anatomy of subsequent rings and gives them a more intense colouration on one of the sides.

Scientists predict that it will be possible to reconstruct the last 150 years of landslide events from this mountain range using dendrochronology (study of geomorphological processes by means of dendrochronology). "The best strategy for studying past landslides is a combination of techniques that estimate the frequency of landslides and the dimensions of the largest landslides (which are usually catastrophic) through historical documents, surveys of the local population, winter monitoring, collection of meteorological and snow-meteorological data, geomorphological mapping and dendrochronology," the scientists points out.

Avalanche danger

Dendrochronology and the research of historical documents can be useful to learn about past avalanches given the fact that humans are now more exposed to the risk of landslides. "In principle, the risk of avalanches has not increased, but the exposure of people and property to this natural phenomenon has, due to the increased number of people frequenting mountain areas during the winter. Faced with a situation of increasing urbanisation in many valleys of the Pyrenees, it is necessary to clarify which area is exposed and to what extent, and to work accordingly," Muntán states.

Although most avalanches occur in remote areas high in the mountains, accidents involving people do also occur, particularly due to the increase of people taking part in mountain sports during the winter in the Pyrenees. The dendrochronologist stresses that "landslides do not have to be very large to injure or affect people."

However, finding about about meteorological conditions and snow cover that might be triggered may help to prevent avalanches. "It is possible to give a certain degree of advanced warning about the possibility of spontaneous triggering of avalanches, although past events must be studied to learn about these conditions ," Muntán affirms.

Mitigation is done by installing special devices in avalanche areas (passive defence) once the area has been studied, or by artificial triggering of avalanches (active defence).


Story Source:

The above story is based on materials provided by Plataforma SINC. Note: Materials may be edited for content and length.


Journal Reference:

  1. Muntán, E.; García, C.; Oller, P.; Marti, G.; García, A.; Gutierrez, E. Reconstructing snow avalanches in the Southeastern Pyrenees. Natural Hazards and Earth System Sciences, 9(5): 1599-1612, 2009.

Cite This Page:

Plataforma SINC. "Reconstruction of the most intense avalanches of the last 40 years in the Catalonian Pyrenees." ScienceDaily. ScienceDaily, 13 January 2010. <www.sciencedaily.com/releases/2010/01/100112124231.htm>.
Plataforma SINC. (2010, January 13). Reconstruction of the most intense avalanches of the last 40 years in the Catalonian Pyrenees. ScienceDaily. Retrieved September 23, 2014 from www.sciencedaily.com/releases/2010/01/100112124231.htm
Plataforma SINC. "Reconstruction of the most intense avalanches of the last 40 years in the Catalonian Pyrenees." ScienceDaily. www.sciencedaily.com/releases/2010/01/100112124231.htm (accessed September 23, 2014).

Share This



More Earth & Climate News

Tuesday, September 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Obama: No Nation Gets Pass on Climate Change

Obama: No Nation Gets Pass on Climate Change

AP (Sep. 23, 2014) — In a forceful appeal for international cooperation on limiting carbon pollution, President Barack Obama warned world leaders at the UN Climate Summit on Tuesday that the globe's climate is changing faster than efforts to address it. (Sept. 23) Video provided by AP
Powered by NewsLook.com
Hundreds of Thousands Hit NYC Streets to Protest Climate Change

Hundreds of Thousands Hit NYC Streets to Protest Climate Change

AFP (Sep. 22, 2014) — Celebrities, political leaders and the masses rallied in New York and across the globe demanding urgent action on climate change, with organizers saying 600,000 people hit the streets. Duration: 01:19 Video provided by AFP
Powered by NewsLook.com
Raw: Protesters Stage Wall Street Climate Sit-in

Raw: Protesters Stage Wall Street Climate Sit-in

AP (Sep. 22, 2014) — A day after over 100,000 people marched against climate change, more than 1,000 activists blocked parts of Manhattan's financial district. Over 100 people, including a person wearing a white polar bear suit, were arrested Monday night. (Sept. 22) Video provided by AP
Powered by NewsLook.com
French FM Urges 'powerful' Response to Global Warming

French FM Urges 'powerful' Response to Global Warming

AFP (Sep. 22, 2014) — French Foreign Minister Laurent Fabius on Monday warned about the potential "catastrophe" if global warming was not dealt with in a "powerful" way. Duration: 01:08 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins