Geological hazard

Summary

A geologic hazard or geohazard is an adverse geologic condition capable of causing widespread damage or loss of property and life.[1] These hazards 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-economics to a large extent (e.g., tsunamis).

Huge landslide at La Conchita, 1995

Sometimes the hazard is instigated by the careless location of developments or construction in which the conditions were not taken into account. 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 and causing 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]

Sudden and slow phenomenaEdit

Sudden phenomena include:

Gradual or slow phenomena include:

Evaluation and mitigationEdit

Geologic hazards are typically evaluated by engineering geologists who are educated and trained in interpretation of landforms and earth process, earth-structure interaction, and in geologic hazard mitigation. The engineering geologist provides recommendations and designs to mitigate for geologic hazards. Trained hazard mitigation planners also assist local communities to identify strategies for mitigating the effects of such hazards and developing plans to implement these measures. Mitigation can include a variety of measures:

In paleohistoryEdit

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.[5] 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.[6]

Known hazardsEdit

See alsoEdit

ReferencesEdit

  1. ^ International Centre for Geohazards Archived March 2, 2008, at the Wayback Machine
  2. ^ Nadim (2006). "Challenges to geo-scientists in risk assessment for sub-marine slides". Norwegian Journal of Geology. 86 (3): 351–362.
  3. ^ Solheim, A.; et al. "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.
  4. ^ Geologic Hazards NationalAtlas Archived 2010-04-30 at the Wayback Machine
  5. ^ 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" (PDF). Science. 241 (4866): 663–668. Bibcode:1988Sci...241..663R. doi:10.1126/science.241.4866.663. PMID 17839077. S2CID 33327812. {{cite journal}}: Check |url= value (help)CS1 maint: uses authors parameter (link)
  6. ^ P.B. Wignall (2001). "Large igneous provinces and mass extinctions". Earth-Science Reviews. 53 (1–2): 1–33. Bibcode:2001ESRv...53....1W. doi:10.1016/S0012-8252(00)00037-4.

External linksEdit

  •   Media related to Geological hazards at Wikimedia Commons
  • International Centre for Geohazards (ICG)