Earth:Geohazard
A geohazard is a geological state that may lead to widespread damage or risk.[1] Geohazards are geological and environmental conditions and involve long-term or short-term geological processes. Geohazards can be relatively small features, but they can also attain huge dimensions (e.g., submarine or surface landslide) and affect local and regional socio-economy to a large extent (e.g., tsunamis).
Geohazards
Human activities, such as drilling through overpressured zones—could result in significant risk, and as such mitigation and prevention are paramount, through improved understanding of geohazards, their preconditions, causes and implications. In other cases, particularly in montane regions, natural processes can cause catalytic events of a complex nature, such as an avalanche hitting a lake causes a debris flow, with consequences potentially hundreds of miles away, or creating a lahar by volcanism.
The continued and multi-disciplinary investigation into the occurrence and implications of geohazards, in particular offshore geohazards in relation with the oil and gas exploration, lead to specific mitigation studies and establishing relevant prevention mechanisms.[2][3]
- (Submarine) Landslides
- Debris flows
- Shallow gas accumulation
- Overpressured zones (including gas and shallow water flows)
- Naturally occurring gas hydrates and their climate-controlled meta-stability
- Mud flows, diapirism and volcanism/volcanoes
- Flood basalt
- Earthquakes and seismicity
- Tsunamis from tectonics and landslides
- Rock falls and landslides
Geohazards in Earth's history
Eleven distinct flood basalt episodes occurred in the past 250 million years, resulting in large volcanic provinces, creating lava plateaus and mountain ranges on Earth.[4] Large igneous provinces have been connected to five mass extinction events. The timing of six out of eleven known provinces coincide with periods of global warming and marine anoxia/dysoxia. Thus, suggesting that volcanic CO2 emissions can force an important effect on the climate system.[5]
Known geohazards
- 2004 Indian Ocean earthquake and tsunami
- 2008 Sichuan earthquake
- 2011 Tōhoku earthquake and tsunami
- The Barrier (located in Garibaldi Provincial Park)
- Usoi Dam a natural landslide dam
References
- ↑ International Centre for Geohazards
- ↑ Nadim (2006). "Challenges to geo-scientists in risk assessment for sub-marine slides". Norwegian Journal of Geology 86 (3): 351–362.
- ↑ Solheim, A.. "2005. Ormen Lange – An integrated study for the safe development of a deep-water gas field within the Storegga Slide complex, NE Atlantic continental margin; executive summary". Marine and Petroleum Geology 22 (1–2): 1–9. doi:10.1016/j.marpetgeo.2004.10.001.
- ↑ Michael R. Rampino & Richard B. Stothers (1988). http://pubs.giss.nasa.gov/docs/1988/1988_Rampino_Stothers_1.pdf "Flood Basalt Volcanism During the Past 250 Million Years". Science 241 (4866): 663–668. doi:10.1126/science.241.4866.663. PMID 17839077. Bibcode: 1988Sci...241..663R. http://www.sciencemag.org/content/241/4866/663 http://pubs.giss.nasa.gov/docs/1988/1988_Rampino_Stothers_1.pdf.
- ↑ P.B. Wignall (2001). "Large igneous provinces and mass extinctions". Earth-Science Reviews 53 (1–2): 1–33. doi:10.1016/S0012-8252(00)00037-4. Bibcode: 2001ESRv...53....1W.
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