tsunamis - natty das exam prep

tsunami

a very large body wave generated in an ocean/large body of water by a displacement of water. wavelengths long, often >100km. short amplitudes until at coast. 10 - 60 minute periods (length in between wave crests)

displacement waves

waves in an ocean/lake that result from shifts in the basement floor/movement of material into water (avalanche), may be seismogenic.

seismogenic wave

potential to generate/trigger seismic activity (earthquake) through shaking of the earth

tidal waves

caused by gravitational force between moon/earth/sun . water not being displaced, but pulled.

wave speed

√gd. g= acceleration, d= depth (meters). round g to 10m/s2. equation most appropriate for shallow water.

2004 sumatra, indonesia

megathrust EQ triggered tsunami, 230,000 people dead. Magnitude 9.1.

2011 japan tohoku

megathrust EQ, inundation maps were underestimated, 25,000 dead

inundation distance

maximum water penetration in land (distance from average coastline at high tide) (within a few cm accuracy)

run-up height

height above average high tide level at the point of maximum distance inland

tsunami hazards in north atlantic

submarine landslides, costal rock avalanches

splash model

numerical model used to simulate the impact of a tsunami wave on a coastline (helps predict the height and distribution of the waves that travel inland)

dart observation system

Deep ocean Assesment and Reporting of Tsunami (observes tsunamis while they happen)

MOST model

Method Of Splitting Tsunami, predicted numerical simulating of a tsunamis lifespan

submarine landslide

Storegga, off Norwegian Continental Shelf, Grand banks Newfoundland 1929.