IB Geography: Geophysical Hazards Revision

Geophysical Hazards is a core part of IB Geography. Revise the key concepts and common mistakes below, then lock them in with the free games.

Key concepts

TsunamiSeries of sea waves generated by underwater seismic, volcanic or landslide displacement.

Boxing Day Tsunami26 December 2004 tsunami from a Mw 9.1-9.3 Sumatra-Andaman earthquake.

Run-upMaximum height a tsunami wave reaches inland above sea level.

DrawbackReceding of the sea before a tsunami arrives — a critical natural warning.

Indian Ocean Tsunami Warning System (IOTWS)Network established from 2006 to provide early tsunami warning in the Indian Ocean.

Risk equationRisk = Hazard × Vulnerability × Exposure ÷ Capacity, used to assess disaster risk.

EyjafjallajökullIcelandic ice-capped stratovolcano whose 2010 eruption disrupted European aviation for several days.

VEIVolcanic Explosivity Index, scaling eruptions from 0 (Hawaiian) to 8 (super-eruptions).

TephraFragmented material ejected from volcanoes including ash, lapilli and bombs.

Pyroclastic flowHot, high-speed mixture of gas, ash and rock fragments flowing downslope.

LaharVolcanic mudflow especially associated with eruptions interacting with snow, ice or rain.

HotspotVolcanic centre fed by a fixed mantle plume, e.g. Hawaii.

MagnitudeLogarithmic measure of seismic energy release on the moment magnitude scale (Mw).

Tohoku earthquake11 March 2011 magnitude 9.0 megathrust earthquake off northeast Japan.

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▶ Two Truths, One Lie ▶ Reveal Race ▶ Connections Grid ▶ Falling Words ▶ Word Web

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Geophysical Hazards

Key concepts

Practise Geophysical Hazards — free games

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