Hawaii's Kilauea volcano is one of the most active volcanoes on Earth. It is, therefore, a perfect location for geological investigation. Forgoing the immediate danger from heat and noxious gases, scientists from a variety of institutions set out in the early 1900s to study Kilauea's ever active caldera, marking one of the first steps in geophysical exploration. In 1909, scientists Thomas A. Jaggar from the Massachusetts Institute of Technology, Frank Perret of the Carnegie Institution of Washington’s Geophysical Laboratory, and Professor Reginald A. Daly of Harvard visited Kilauea with the intention of creating a nearby permanent location for volcanological studies.
The plan was set into action and by 1911, Jaggar and Perret established the first observation station on the rim of the Halema’uma’u crater. A year later, the Hawaiian Volcano Observatory was built at the edge of the Kilauea caldera.
In January of 1912, Perret officially began his volcanological studies at Halema’uma’u from his observatory station. Perret was primarily intrigued by the constant motion of the active lava lake and sought to develop an understanding of its complex circulation system.
For several of his experiments, Perret, with the assistance of Jaggar, used a devise called a seger cone. Seger cones were made from a mixture of salt and clay. They were used to measure the temperature of the lava because the cones melted at a known temperature. Therefore, by registering where the cone melted, Perret could distinguish a ballpark temperature for the lava. 1,000 degrees Celsius was the highest temperature recorded.
Perret also used a less accurate method, the thermocouple, to measure lava temperature. To set up the experiment, scientists stretched a cable over the entire 300 meter width of the crater.
The thermocouple and soldering bucket with the ability to withstand extreme temperatures were attached to the cable. The bucket was then lowered via pulley into what the scientists named “Old Faithful,” the perennial central fountain. The bucket captured lava samples, providing the scientists with enough information to take back to the laboratory for further study. During this process, three sets of equipment were destroyed by the lava.
Perret transferred the new information from lava temperature to the laboratory to solve the age old question on almost every volcanologist’s mind. Why were scientists unable to distinguish one particular mineral from the molten rock?
The answer lay in Perret’s temperature data. Certain minerals melt and change at temperatures of at least 450 degrees Celsius. Because the lava was much hotter than this, minerals were constantly changing from one type to another. Thus, scientists couldn’t find just one mineral in magma. They could instead pick out dozens.
Gas was another interest of Perret’s. With the help of E. S. Shepherd and Arthur L. Day, Perret conducted a chemical analysis of Kilauea’s volcanic gas. The scientists found that water vapor was present in the gas, lending credit to one side of a very controversial subject in the late nineteenth century.
The Kilauea volcano study and the data obtained from it made possible later laboratory experiments that helped scientists to better understand lava, gas, and the minerals in molten rock. According to former Geophysical Laboratory director, the late Hatten S. Yoder, Jr., the experiments of 1917 remain some of the best ever obtained from active lava. Though one of the earliest accounts of geophysical field research, the Kilauea studies were definitely some of the most fascinating and scientifically significant in the Geophysical Laboratory’s early history.
Wright, Thomas L., Taeko Jane Takahashi, and J. D. Griggs, Hawai’i Volcano Watch, University of Hawaii Press, 1992.
Yoder, Hatten S., Jr. Centennial History of the Carnegie Institution of Washington, Volume III, Cambridge University Press, Cambridge, 2004.
Day, Arthur L., The volcano Kilauea in action, Journal of the Washington Academy of Sciences, 5, 553, 1915.