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).
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]
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:
Geologic hazards may be avoided by relocation. Publicly available databases, via searchable platforms,[7] can help people evaluate hazards in locations of interest.
Mapping geohazards using conventional or remote sensing techniques[8] can also help identify suitable areas for urban development.
^Nadim (2006). "Challenges to geo-scientists in risk assessment for sub-marine slides". Norwegian Journal of Geology. 86 (3): 351–362.
^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.