Earthquake and Tsunami Concepts

These flashcards cover key vocabulary and concepts related to earthquakes and tsunamis based on the provided lecture notes.

Tohoku Earthquake

The strongest recorded earthquake in Japan, measuring 9.0 on the Richter scale.

Epicenter

The location on the surface directly above the point where an earthquake originates.

Focus (Hypocenter)

The point of initial breaking or rupturing within the Earth where an earthquake originates.

Seismic Waves

Waves produced by the sudden release of strain energy from a fault rupture.

P Waves

Primary waves that are the fastest seismic waves and can travel through solids, liquids, and gases.

S Waves

Secondary waves that are slower than P Waves and can only travel through solids.

Faulting

The process of fault rupture where rocks break and are displaced due to stress exceeding their strength.

Strain

The deformation observed as a result of stress applied to rocks.

Liquefaction

The phenomenon where loosely packed, water-logged sediments lose strength and behave like a liquid during an earthquake.

Tsunami

A series of ocean waves caused by large disturbances such as earthquakes, seafloor displacement, or underwater landslides.

Warning System

A system made up of seismographs and sensors to detect earthquakes and measure sea level changes to issue tsunami alerts.

Runup maps

Maps that show areas vulnerable to tsunami inundation and the levels to which water is anticipated to rise.

Distant Tsunami

A tsunami that travels out to sea without impacting land immediately.

Local Tsunami

A tsunami that travels towards land, often arriving first and causing immediate effects.

Seismometer

An instrument used to measure the intensity and duration of seismic waves during an earthquake.

Convergent seismicity

Regions where the largest and most active earthquakes occur, typically at subduction zones.

Modified Mercalli Scale

A qualitative scale measuring the effects of an earthquake based on eyewitness accounts and damage.

Earthquake Cycle

The sequence of events leading up to and including an earthquake, involving periods of inactivity, strain accumulation, and rupture.

Tsunamis are triggered by

seafloor displacement, landslides, large earthquake