Monitoring Volcanoes

• Volcanic Explosivity Index:

  From 1 - 8, humans have never experienced 7/8
• Risk Mapping


  Studying the geological history of a volcano can give info. About the frequency of events and types of hazards
• Locating Magma Chambers


  Like a sponge filled with water.

  Place seismometers - record waves generated by earthquakes. If waves encounters magma it slows down

  By comparing recordings you can find the shape and size of the chamber
• Earthquakes


  Short Period: Cause by fracturing of rock as the magma forces it’s way upward

  Long Period: Earthquakes where shaking continued longer than usual - linked to increase pressure in magma chamber

  Harmonic Tremors: Long lasting rhythmic vibrations due to magma moving in the vent

  Increased earthquake activity is one of the factors used to predict eruptions
• Ground Movement


  Swelling is measured using tiltmeters and GPS to measure vertical and horizontal movement

  Swelling corresponds to magma moving under the volcano
• Gas Emissions


  Increased gas suggests magma near the surface
• Changes in Groundwater


  borehole and well measurements. Increased gas pressure will cause water levels to rise