Montag, 22. Februar 2010

Landslide of Leisach (Austria)

A landslide near the village of Leisach (East-Tyrol, Austria;46°48`36`` N / 12°45`02`` E), occured in the night between the 19. and 20. february, has dammed up the river Drau and buried the street and trainrails between Italy and Austria. The landslide is 100m wide and 10m thick.
I´m expecting more to come in the next weeks and months...

Fig.1. Foto/Copyright: Robert Gutwenger Lienz (source)

Montag, 15. Februar 2010

Landslide in Calabria

Landslide in Calabria (South-Italy), town of Maierato (38°42`29``N 16°11`33``E) - 15.02.2010:

UPDATE 17.02.2010: Video of landslide-aftermath

UPDATE 16.02.2010: Mass evacuation of all 2.300 inhabitants of Maierato, a town in the province of Vibo Valentia: an entire side of the mountain which is located near the town collapsed yesterday morning and caused a huge landslide. The landslide - says the mayor Sergio Rizzo - threatens an important part of town and we have unfavourable weather conditions, so we decided not to risk. The first 300 people were evacuated from their homes yesterday evening, but this morning began the evacuation of the entire town. Rainy weather and resulting mass wasting has caused problems also in other parts of Calabria and Sicily.

Fig.2. Carta Geologica della Calabria Foglio 241 1:25.000 (click to enlarge)

The landslide developed in Pliocene-Miocene marls and argillaceous deposits, and showed first signs of reactivation 10 days ago.

Fig.1. Extract of the geological map of Maierato, by Dr. E. Bonino. M= Miocene, P= Pliocene, d= recent deposits. Area of landslide red contour. See also this WebGIS application.


UPDATE: Map of MAIERATO with preliminary risk zonation and delimination of landslides

VIDEO (16.10.2010)

VIDEO released 15.02.2010:

Freitag, 12. Februar 2010

Sea-Level Highstand disproves ice-age CO2 connection?

The ice ages on Earth could be influenced by CO2 levels differently than previously believed. The study of speleotherms in the cave of Vallgornera situated on the Spanish island of Mallorca revealed that the polar caps were as small as today 81,000 years ago - despite lower CO2 levels.
A team of scientists of the University of Iowa has studied aragonitic and calcitic mineral deposits from five caverns situated; depending of the sea level - itself varying by the amount of “captured” water in ice caps up to 130m - the caves were inundated and different mineralogical deposition occurred.

The dated samples suggest that the sea level around 81,000 years ago was about a meter above the current value. "We have reconstructed the sea level with really high precision," says researcher Doral to the German newspaper “SPIEGEL ONLINE”.Co-author Bogdan Onac from the University of South Florida explains that Mallorca is ideal for this kind of research because tectonically stable and the observed variations should be “true” variations of sea level, not falsified by geological movements or isostatic rebound.

If the sea level 81,000 years ago was actually where the researchers suggest, an interesting problem arises: it doesn’t support the calculated 100.000-year cycle of glacial advances. Also it contradicts the direct ice-CO2 connections - despite low CO2 concentrations, and weaker greenhouse effect, the ice caps on earth were not as great as previously tough, and in dimensions comparable to modern conditions.
So are climate denialists right, and is there no such thing as anthropogenic greenhouse effect?
No, the authors want to take the results in a scientific context: the research doesn’t make claims about the global temperature during this time, only about the possible ice volume, and the amount of ice is not only controlled by temperature, but also for example by insolation of the sun, stronger 80.000 years ago then today. "What happened 80,000 years ago, is not the same as what happened today," said Onac.

REFERENCES:
DORALE et al. (2010): Sea-Level Highstand 81,000 Years Ago in Mallorca. Science Vol.327(5967): 860 - 863