Magnitude and Intensity

PhiVolcs

Is a national institution that monitors and forecasts volcanic eruptions, earthquakes, and tsunamis.

Magnitude

a measure of the total energy released by an earthquake at its source (focus).

Ritcher Scale

• Charles F. Richter in 1935

• Measure earthquake magnitude based on seismic wave amplitude

• Ranging from less than micro earthquakes to over catastrophicearthquakes)

Seismograph

Is a device that measures and records vibrations in the ground caused by earthquakes.

Intensity

the strength of an earthquake as felt by people and the damage it causes to the environment and structures.

Modified Mercalli Intensity Scale

• Proposed by
  Giuseppe Mercalli in
  1902

• Measure the
  intensity of ground
  shaking caused by an
  earthquake

Philippine Earthquake Intensity Scale

Philippine version of the Mercalli scale that has only 10 stages