22. The Ohiki, first amphibian truck, with passengers Isabel Jaggar, Tahara, L. A. Thurston, Jaggar, and Ted Dranga, 1928
23. Lava flow entering village of Hoopuloa, 1926
24. Lava flow of 1926 Mauna Loa eruption approaching Hoopuloa Village, which was destroyed. Photo section U.S. Army Air Force
Lassen Peak is the southernmost volcano on the line where the Cascade Range merges with the Sierra Nevada. The line of volcanoes extends beyond Mount Baker into Canada. North of Lassen is the Glass Mountain region where there are obsidian lava flows. Like Mount Shasta, Lassen is a volcano of very few recent eruptions, but there were at least two outbreaks in the nineteenth century. These two volcanoes resemble Pelée and Soufrière. Their linear quality implies a long ragged rift in the earth’s crust, and south of Lassen there is suggested an offset rift at Mount St. Helena, near the famous superheated steam of Geyserville. This is near the northern end of the great San Andreas rift, which extends many hundreds of miles southeast of San Francisco. The rift shifted in a north-south direction during the earthquake of 1906, and is one of the many evidences that the north-south faults of California are all a part of the faulting up, over lava, of the Cordillera, relative to downsunken Pacific Ocean slabs.
I put Finch in charge of Aleutian Islands seismographs, as well as the one he was to establish at Mineral. With Wilson as seismologist and instrument designer in Hawaii, we started constructing horizontal pendulums, like those used in Hawaii, making the weights out of large iron pipes, to be filled with sand at the place of operation. These were two-component seismographs, recording on a single chronograph drum. We sent one to the Coast Survey station at Sitka and built two more for Kodiak and Unalaska. Finch built and set up his own seismograph at Mineral. He started systematic surveys of the temperatures of hot springs and steam jets in different parts of Lassen Park and kept close contact with the Geological Department of the University of California at Berkeley. Lassen was the subject of geological surveys by Anderson and Finch, and later the park area was studied by Howel Williams.
I went to Washington to see government authorities, particularly Professor Charles F. Marvin, Chief of the Weather Bureau, and Dr. G. O. Smith, Director of the Geological Survey. I can never express my indebtedness to Marvin, a good designer who built an inverted pendulum seismograph in Washington. Finch had worked with Marvin when he was weather observer in airplanes based on Ireland during the first World War. Hence methods of government contact and reports, in the early days of our Observatory, were kindly guided by Marvin. The Weather Bureau was a place of self-recording instruments, something new for geology, and much needed for volcano observation. For weather is a matter of present changes, whereas geology had long been a matter of ancient specimens.
Director Smith was instrumental in calling a meeting in Washington, of scientists of all bureaus interested in the Aleutian Islands. I was selected to lead the symposium, which included representatives of climatology, biology and fisheries, geology and geochemistry, oceanography and geodesy, hydrographic charting, gravity, and magnetism. There proved to be great interest in the Alaskan Peninsula and the islands, and the Survey published a special bulletin on the symposium.