SNOW AVALANCHE SCIENCE AND MANAGEMENT GEO-3139 – 10 ECTS
Kurset i snøskredvitenskap har gått noen år allerede ved UiT, men årets kurs er det beste, ifølge UiTs Christopher D’Amboise. Han er postdoc hos oss ved IG og har vært med å undervise i kurset denne vinteren. Jeg snakket med han for å høre hvordan kurset har vært sålangt i år.
With the news of Norway ‘split in two’ this week from a bridge collapse we are facing the reality, yet again, of a society dependent on road access through mountainous terrain. I discuss why we continue to be surprised by these events, and what we can do to safeguard our roads in the future
The rockslide and rock avalanche desposit Skredkallen is located on the island Vannøya, a large mountainous island on the outer coast of Troms. It contains spectacular large craggy mountains (up to 1000 m directly from sea level), white sandy beaches, exposed tundra, reindeer and even it’s own fjord! The island is accessed by ferry only, but is well worth a day or weekend visit from Tromsø. In my humble opinion, this is one good looking rockslide. The work presented here involved some Sherlock-style detective skills from UiT’s finest geomorphologists, geochronologists, Quaternary geologists and engineering geologists.
Vi har fått et lite innblikk i hva vi har gjort i felt på Dusnjárga allerede (Les om det her). Det andre fjellskredet som jeg har med i studiet mitt er en ustabil fjellside i Kåfjorden som heter Gámanjunni-3. Det er en bred fjellrygg som har flere ustabiliteter og gamle skredarr i den dalsiden som vender mot vest. Fjellet har vært et punkt av interesse for NGU og NVE i flere år, og i 2016 ble det klassifisert som et høyrisikoobjekt basert på bevegelses hastighet og strukturer.
Ever wondered how a rockslide might taste? The Apremont wine variety may be the closest you can get. The grapes are grown on the debris of a large rock avalanche from Mont Granier in the Chartreuse mountains, France. The flavour is a distinctively light and dry with floral, mineral characters.
A catastrophic landslide occurred in 1248. A large portion of the mountain failed, forming a rock avalanche covering the valley and several villages. Some reports state the debris covered more that 6 x 6 km, and destroyed 7 villages. Fatality estimates vary from 1000 to 7000, based on various records made by monks at the time. The failure followed relentless rain which saturated the limestone in the upper portion of the slope, causing a failure along the interface with marl below (source).Continue reading Bottled rockslide
Carly is a rock detective who hunts for evidence of ancient earthquakes around the world. She completed her PhD in Tromsø and a postdoc at McGill University in Montreal. In this article, Carly provides some background about earthquakes, and then goes on to tell us how she identifies ancient earthquakes in rocks. This tool is also applied to landslides. Next time you are hiking in the Norwegian mountains, you may just be stepping on signs of an old earthquake or landslide!
Like landslides, earthquakes are dangerous natural phenomenon that cause loss of human life and costly damage to infrastructure. And like coastal landslides, earthquakes can cause tsunamis, which compound the seriousness of their effects. Earthquakes can also trigger landslides and rockfalls when they happen in mountainous areas. Humans have been recording earthquakes for nearly 4000 years, and the deadliest earthquake in recorded history occurred in 1556 in Shaanxi, China where it is estimated that around 830 000 people died. The magnitude was around 8. The highest ever recorded magnitude for an earthquake was 9.5 for the 1960 Valdivia earthquake in Chile (Kanamori, 2006). There are several methods to measure earthquakes, and the most common scale used to estimate the magnitude of an earthquake today is the moment magnitude scale (MMS). The MMS measures shaking during an earthquake. The MMS replaces the outdated Richter scale, which cannot adequately measure earthquakes over magnitude 8. The MMS is a log scale, which means that at magnitude 9.5, the Valdivia earthquake shook around 32 times more than the magnitude 8 earthquake at Shaanxi. Norway’s most significant earthquake happened in 1904, in the Oslofjord area. It had a magnitude 5.4, and while there were no casualties, damage was caused to buildings. Continue reading Earthquakes: the landslides of the deep
Veslemannen, et ustabilt fjellparti i Romsdalen i Møre og Romsdal kommune, fikk mye oppmerksomhet i media mellom 2014 og 2019. «Hele» Norge fulgte nøye med på når fjellsiden skulle ramle. Beboerens i dalen nedenfor fjellet ble evakuert hele 16 ganger og Raumabanen ble stengt i perioder. I lys av en nylig publisert artikkel av Kristiansen et al. (2021) så tar vi en titt på Veslemannen. Hva skjedde med Veslemannen, og hvorfor er det så vanskelig å presist varsle skredet? Continue reading Hva var greia med Veslemannen?