Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Traces of a tsunami in Sweden

23.05.2006


145 million years ago Scandinavia was hit by a tsunami, probably more intense than the one that hit Southeastern Asia in December 2004. Traces of this ancient tsunami are still left and these have been discovered by the geologists Vivi Vajda and Jane Wigforss-Lange at Lund University. The scientific results will soon be published in the journal Progress in Natural Science.



The site is located at Eriksdal, in the southernmost province of Sweden, Skåne. Scandinavia and the Baltic formed a continent 145 million years ago, around the Jurassic-Cretaceous transition. The coast line cut through Skåne and the area around Eriksdal was a delta environment. At this time Sweden was situated at the same latitude as the Mediterranean of today and the climate was globally warm, not even the poles were ice capped. In Scandinavia tree ferns, gingkoes and cycads were thriving and the fauna was dominated by dinosaurs. The coast was inhabited by sharks, crocodiles and tetrapods (now extinct giant amphibians).

The 30 metre thick section in Eriksdal is hid in a farmland and can only be accessed by extensive digging and the sediments are tilted so the layers are vertical. In the sediments we found fossils of fish, mussels, snails mixed with landplants, says Vivi Vajda. We first interpreted these beds as storm deposits but microscopical samples revealed a total mix of pollen, plant fragments and fungal spores both within the shellbed and just above, signs that indicate that material from land was transported by the same wave as the one causing the accumulation of the shell bed. Besides, the mussels and the snails were extremely well preserved indicating a single depositional event and not a storm, which would have left the shells broken and eroded. We started to suspect that a tsunami had hit the area but we didn’t have enough evidence at the time to put the theory forward.


But Vajda and Wigforss-Lange had found a probable cause for the tsunami. Norwegian scientists had in 1996 discovered a 145 million old crater at the bottom of Barents sea, North of Scandinavia. The crater was called the Mjölnir crater, named after the hammer which the god Thor used to fight giants with. The impact was catastrophic. It created a crater in the Mesozoic shelf of around 40 km in diameter and about 3.6 km deep and generated major shockwaves and tsunamis that travelled across the shelf. It is likely that tsunamis generated by this impact may have propagated southwards along the narrow intracontinental seaways affecting coastal areas in the Norwegian-Danish Basin, leaving such traces as the anomalous sequence recorded at Eriksdal.

The turning point for us was when we read the results published by a French research group, says Vivi Vajda. They studied sediments from the Boulonnais area in northern France which were deposited at the same time as the ones at Eriksdal and they interpreted the structures as tsunami deposits. Interestingly, this was put forward in 2000, at a time when tsunami wasn’t a concept in every man´s mind.
The 2004 Tsunami has attracted geologists from all over who want to learn more about the sedimentary structures that are left by tsunamis in order to interpret events in the past. In Indonesian Banda Acheh the tsunami left shells and other debris in depressions as it withdrew from the land. Usually there are also erosional contacts at the base of these beds where the tsunami has partly removed underlying sediments. Jane Wigforss-Lange, specialised in sedimentology also recorded these structures in the Swedish layers.

Vajdas’ and Wigforss-Langes’ discovery was made when they worked within an UNESCO sponsored project with aims to make global correlations of Jurassic and Cretaceous sediments. Both geologists will proceed with investigations in Eriksdal and other places.

Göran Frankel | alfa
Further information:
http://www.geol.lu.se/

More articles from Earth Sciences:

nachricht International team reports ocean acidification spreading rapidly in Arctic Ocean
28.02.2017 | University of Delaware

nachricht Secrets of the calcerous ooze revealed
28.02.2017 | Washington University in St. Louis

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

New technology offers fast peptide synthesis

28.02.2017 | Life Sciences

WSU research advances energy savings for oil, gas industries

28.02.2017 | Power and Electrical Engineering

Who can find the fish that makes the best sound?

28.02.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>