Typical geologic hazards or other adverse conditions evaluated and mitigated by an engineering geologist include: fault rupture on seismically active faults; seismic and earthquake hazards (ground shaking, liquefaction, lurching, lateral spreading, tsunami and seiche events); landslide, mudflow, rockfall, debris flow, and avalanche hazards; unstable slopes and slope stability; erosion; slaking and heave of geologic formations, such as frost heaving; ground subsidence (such as due to ground water withdrawal, sinkhole collapse, cave collapse, decomposition of organic soils, and tectonic movement); volcanic hazards (volcanic eruptions, hot springs, pyroclastic flows, debris flow, debris avalanche, Volcanic gas emissions, volcanic earthquakes); non-rippable or marginally rippable rock requiring heavy ripping or blasting; weak and collapsible soils, foundation bearing failures; shallow ground water/seepage; and other types of geologic constraints. An engineering geologist or geophysicist may be called upon to evaluate the excavatability (i.e. rippability) of earth (rock) materials to assess the need for pre-blasting during earthwork construction, as well as associated impacts due to vibration during blasting on projects. Soil and rock mechanics Soil mechanics is a discipline that applies principles of engineering mechanics, e.g. kinematics, dynamics, fluid mechanics, and mechanics of material, to predict the mechanical behaviour of soils. Rock mechanics is the theoretical and applied science of the mechanical behaviour of rock and rock masses; it is that branch of mechanics concerned with the response of rock and rock masses to the force-fields of their physical environment. The fundamental processes are all related to the behaviour of porous media. Together, soil and rock mechanics are the basis for solving many engineering geology problems. Methods and reporting The methods used by engineering geologists in their studies include geologic field mapping of geologic structures, geologic formations, soil units and hazards; the review of geologic literature, geologic maps, geotechnical reports, engineering plans, environmental reports, stereoscopic aerial photographs, remote sensing data, Global Positioning System (GPS) data, topographic maps and satellite imagery; the excavation, sampling and logging of earth/rock materials in drilled borings, backhoe test pits and trenches, fault trenching, and bulldozer pits; geophysical surveys (such as seismic refraction traverses, resistivity surveys, ground penetrating radar (GPR) surveys, magnetometer surveys, electromagnetic surveys, high-resolution sub-bottom profiling, and other geophysical methods); deformation monitoring as the systematic measurement and tracking of the alteration in the shape or dimensions of an object as a result of the application of stress to it manually or with an automatic deformation monitoring system; and other methods. The fieldwork