#geological_phenomenon  a natural phenomenon involving the structure or composition of the earth
  supertype:  natural_phenomenon__naturalphenomenon  all non-artificial phenomena
  subtype:  earthquake__quake__temblor__seism  shaking and vibration at the surface of the earth resulting from underground movement along a fault plane of from volcanic activity
     subtype:  seismic_disturbance__seismicdisturbance__shock  an instance of agitation of the earth's crust
     subtype:  earth_tremor__earthtremor__tremor__microseism  a small earthquake
        subtype:  aftershock  a tremor (or one of a series of tremors) occurring after the main shock of an earthquake
        subtype:  foreshock  a tremor preceding an earthquake
     subtype:  seaquake__submarine_earthquake__submarineearthquake  an earthquake at the sea bed
  subtype:  alluvial_fan__alluvial_cone  a fan-shaped deposit where a fast flowing stream flattens out
  subtype:  cataclysm__catastrophe  a sudden violent change in the earth's surface
  subtype:  continental_drift__continentaldrift  the gradual movement and formation of continents (as described by plate tectonics)
  subtype:  sedimentation__deposit__alluviation  the phenomenon of sediment or gravel accumulating
     subtype:  lode__load  a deposit of valuable ore occurring within definite boundaries separating it from surrounding rocks
        subtype:  mother_lode__champion_lode  the main vein of ore in a deposit
  subtype:  inundation__flood__deluge__alluvion  the rising of a body of water and its overflowing onto normally dry land
     subtype:  debacle  flooding caused by a tumultuous breakup of ice in a river during the spring or summer
     subtype:  flash_flood__flashflood  a sudden local flood of great volume and short duration
        subtype:  floodhead  a wall of water rushing ahead of the flood; "we were lucky to be safe when the floodheads hit"
  subtype:  frost_heave__frost_heaving  upthrust of ground or pavement caused by the freezing of moist soil
  subtype:  volcanism  the phenomena associated with volcanic activity

No statement uses or specializes geological_phenomenon; click here to add one.