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.

Marine geohazards in particular constitute a fast-growing sector of research as they involve seismic, tectonic, volcanic processes now occurring at higher frequency, and often resulting in coastal sub-marine avalanches or devastating tsunamis in some of the most densely populated areas of the world [2][3]

Such impacts on vulnerable coastal populations, coastal infrastructures, offshore exploration platforms, obviously call for a higher level of preparedness and mitigation.[4][5]

Speed of development

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Sudden phenomena

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Sudden phenomena include:

Slow phenomena

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Gradual or slow phenomena include:

Evaluation and mitigation

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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 paleohistory

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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.[9] 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.[10]

Known hazards

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See also

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References

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  1. ^ International Centre for Geohazards Archived March 2, 2008, at the Wayback Machine
  2. ^ de Lange, G.; Sakellariou, D.; Briand, F. (2011). "Marine Geohazards in the Mediterranean: an overview". CIESM Workshop Monographs. 42: 7–26.[1]
  3. ^ Cardenas, I.C.; et al. (2022). "Marine geohazards exposed: Uncertainties involved". Marine Georesources and Geotechnology. 41 (6): 589–619. doi:10.1080/1064119X.2022.2078252. hdl:11250/3058338. S2CID 249161443.
  4. ^ Nadim (2006). "Challenges to geo-scientists in risk assessment for sub-marine slides". Norwegian Journal of Geology. 86 (3): 351–362.
  5. ^ 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.
  6. ^ Geologic Hazards NationalAtlas Archived 2010-04-30 at the Wayback Machine
  7. ^ Toussaint, Kristin (2021-09-29). "Are environmental hazards threatening your home? This website will show you". Fast Company. Retrieved 2022-06-13.
  8. ^ Tomás, Roberto; Pagán, José Ignacio; Navarro, José A.; Cano, Miguel; Pastor, José Luis; Riquelme, Adrián; Cuevas-González, María; Crosetto, Michele; Barra, Anna; Monserrat, Oriol; Lopez-Sanchez, Juan M.; Ramón, Alfredo; Ivorra, Salvador; Del Soldato, Matteo; Solari, Lorenzo (January 2019). "Semi-Automatic Identification and Pre-Screening of Geological–Geotechnical Deformational Processes Using Persistent Scatterer Interferometry Datasets". Remote Sensing. 11 (14): 1675. Bibcode:2019RemS...11.1675T. doi:10.3390/rs11141675. hdl:2158/1162779. ISSN 2072-4292.
  9. ^ Michael R. Rampino; Richard B. Stothers (1988). "Flood Basalt Volcanism During the Past 250 Million Years". Science. 241 (4866): 663–668. Bibcode:1988Sci...241..663R. doi:10.1126/science.241.4866.663. PMID 17839077. S2CID 33327812.
  10. ^ 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.
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