Geology

Tim Orr (with Sam), Geologist, United States Geological Survey (USGS), KilaueaMr. Orr is a staff geologist at the Hawaiian Volcano Observatory situated right next to Kilauea on the Big Island of Hawaii. Kilauea is an effusive shield volcano, active for much longer than recorded history. Western observers began recording their observations of the volcano beginning in the early 1800s. Reading Mark Twain’s account of his first experience at Kilauea on November 16, 1866 is really something (imagine riding on horseback at night to a small viewing shack on the far side of the caldera!). The most recent eruption at Pu’u O’o began in 1983, and the lava from this flank eruption has destroyed the village of Kalapana downslope. While Kilauea generally does not have explosive eruptions (like Mt. St. Helens), conditions change periodically such that massive rocks are tossed great distances from the caldera.

A team of scientists with the USGS studies Kilauea at the Hawaii Volcano Observatory right on the rim of the massive crater. Their work helps civil defense officials keep the local residents informed about potential volcanic hazards, such as the path and speed of a lava flow and air quality problems due to the volcanic gases. Knowledge developed at Kilauea is also used to inform other scientists around the world about volcanoes so they can try to predict when conditions will support a massive eruption. Being able to predict major changes in a volcano’s status may help people evacuate in time.

As a staff geologist for the USGS, Mr. Orr gathers samples of molten lava weekly to measure trends in temperature and chemistry. These data help scientists understand the “plumbing” underlying the volcano, and also estimate eruption potential. This is hazardous work – he wears fire retardant suits and rushes in quickly with hammer in hand to grab a sample and dunk it in a bucket of water to cool it off. Then he takes it back to the lab to measure the mineral content. From this, he can gauge the temperature of the lava and make estimations about eruption potential by comparing it to previous samples.

This sample is basaltic (the type of rock) scoria (blown out) lapilli (small size, approx. 2mm-10cm)

This sample is basaltic (the type of rock) scoria (blown out) lapilli (small size, approx. 2mm-10cm)

Tim Orr (with Sam), Geologist, United States Geological Survey (USGS), Kilauea

Fire retardant gloves and hammer used to grab molten lava sample.

Fire retardant gloves and hammer used to grab molten lava sample.

Thermal scanner used to detect hot spots which might merit sampling.

Thermal scanner used to detect hot spots which might merit sampling.

How did Mr. Orr decide to become a geologist? As a boy, he lived near Yellowstone’s geysers, triggering an interest in the earth and the natural sciences. Then when he was about 12, Mt. St. Helens erupted and spewed ash all over the family’s car. This clinched his interest in geology and he went on to study the subject in college, finally earning his Master’s degree in geology. He has worked in Alaska and Hawaii with the United States Geological Survey (USGS) and really enjoys his job. We were thankful for his time during our visit to the Big Island – we certainly understood much more about the volcano we visited, the machinations under our feet creating the steam vents, and the uniquely interesting field of volcanology.

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