GEOL 205: Hawaiian Earthquakes

According to plate tectonic theory, almost all of the Earth's large earthquakes are found along plate boundaries. Well, there has to be an exception to every rule, and we are living on one. Hawaii is about as far from a plate boundary as you can get on our planet, yet in the past 150 years, we have had several magnitude 7 earthquakes and one quake in 1868 that is estimated to be a magnitude 8. So what's up? Is plate tectonic theory totally wrong? Or are there perhaps other ways to shake the Earth?

Some additional reading about Hawaiian earthquakes can be found at these sites.

This is a short overview of the types of Hawaiian Earthquakes and the record Historical Earthquakes and Hazards

Field Trip along the "Earthquake Trail"in Hawaii Volcanoes National Park. This is a great guided tour of earthquake areas inside and outside the Park.

This is an interactive map and table of recent earthquakes on Hawaii Recent Earthquakes

This is a scale for the intensity of an earthquake, which is different from the MagnitudeMercalli Scale

This great site will give you a good overview of How earthquakes work and how they are measured. Read this if you don't know anything about earthquakes.

Types of Hawaiian Earthquakes

Earthquakes > 5.0 in Hawaii



HVO library after Kaoiki earthquake (1983, about M 6)



Stations of the USGS HVO Seismic Network



Magmatic, Edific, Lithospheric



Shallow and basal quakes along ERZ



Time distance for both rift zones



Cross section of Kilauea Conduit



Southwest rift zone, depth section along fault



East rift zone, depth section along fault



Flank Tectonics

South flank tectonics (Endo...)



Fault areas of 1886 and 1975 quakes



1975 isoseismals



1973 Honomu quake



1886 isoseismals (all islands)



1886 isoseismals (big island)



Typical south flank focal mechanism



South flank focal mechanisms



South flank slip vectors



Microplate Model for Hawaiian Tectonics

Big Island tectonic plate model



Conduit shearing at basal DCL



Basal seismicity delineates active flank structure



Boundaries of active flank plus topo section



Kinematics of rift zones



Vertical area of Big Island active rift zones



Reconstruction of ERZ offset from Mauna Loa NERZ



Examination Questions

  1. Describe the three classes of earthquakes in Hawaii? How do each form? Which class is the most dangerous?
  2. Describe the difference between the 3 principal types of seismic activity associated with eruptions (you can draw them). What causes the different seismic behaviors and how are the earthquakes interpreted?
  3. Explain the two possible fault models for the south flank of Kilauea. Is it possible to use earthquake focal mechanisms to distinquish between these two models? Explain how the relationship between the area of the fault and the magnitude of the earthquakes led seismologists to favor one model over another.
  4. Describe how the summit magma chamber and deep feeder system are located using earthquakes.
  5. What are the differences between magnitude and intensity? How were intensities used to reconstruct the location of the 1868 earthquake?

If you have comments or suggestions, email me at kenhon@hawaii.edu