- Geologic hazards
A geologic hazard is one of several types of adverse geologic conditions capable of causing damage or loss of property and life. These
hazard s can consist of sudden or slow phenomena:
*avalanche s (snow, rock, or air & snow) and its runout
*earthquake s and earthquake-triggered phenomena
*fault rupture (displacement of theterrain or ground along ageological fault ), recent (active) fault (exhibiting actual movement or seismic activity)
*forest fire s (espec. inmediterranean areas)
*ice jam s or iceimpact (Eisstoß) on rivers or below aglacier
*landslide (lateral displacement of earth materials on a slope or hillside)
*mudflow s (avalanche-like muddy flow of soft/wet soil and sediment materials, narrow landslides)
*pyroclastic flows
*rock fall s,rock slide s, (rock avalanche ) anddebris flow s
*torrent s (flash flood s, rapid floods or heavy current creeks with irregular course)
* volcanic eruptions,lahar s andash fall s.Rather gradual or slow phenomena are e.g.:
*alluvial cone s (e.g. at the exit ofcanyon s orside valley s)
*caldera development (volcanoes)
*geyser deposits
* ground settlement due to consolidation of compressible soils or due tocollapse able soils ("see also compaction)
* groundsubsidence ,sag s andsinkhole s
*liquefaction (settlement of the ground in areas underlain by loose saturated sand/silt during an earthquake event)
*sand dune migration
* shoreline and waveerosion
*thermal spring sSometime the hazard is instigated by man through the careless location of developments or construction in which the conditions were not taken into account.Geologic Hazard Evaluation
Geologic hazards are evaluated by an
engineering geologist educated, trained and experienced inengineering geology for their, investigation and analysis, often in conjunction with ageotechnical engineer . The engineering geologist is qualified to formulate recommendations for the mitigation of the hazards. Mitigation can include avoidance of the hazards or relocation; construction ofslope stabilization measures (earth buttress ,retaining wall s,diversion wall s,shear pin s,tieback s,soil nail s orsoil anchor s,revetment s, injection ofgrout or concrete, deep foundations,tunnel s,subdrain s), and other measures.
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