Richard P. Von Herzen, a marine geophysicist whose pioneering work tracked the heat that flowed into the ocean from the earth's interior, died Jan. 28 in Portola Valley of vascular disease, according to his daughter, Lane Von Herzen. He was 85.
Von Herzen conducted his early research at the Scripps Institution of Oceanography in La Jolla before moving to the Woods Hole Oceanographic Institution on Cape Cod.
His work provided key evidence for the theory of plate tectonics and helped reveal the existence of deep-sea ecosystems rich in strange creatures that did not require photosynthesis to survive.
"In both cases he saw ahead of everybody else two simple experiments you could do to test whether these hypotheses were correct," said John Sclater, a Scripps marine geologist and geophysicist who co-led a 1972 scientific cruise with Von Herzen.
Von Herzen's early work helped to confirm a contentious idea proposed in the early 20th century: That the continents on the earth's crust were not fixed but had moved over time (an idea intuitively supported by the way that South America seemed to neatly nestle in the crook beneath West Africa).
His teams measured heat flow at undersea volcanic ridges to show how welling magma formed new seafloors, which spread, cooled and were eventually recycled back into the earth's mantle.
The process was known as seafloor spreading, and it provided key evidence for plate tectonics.
In 1972, Von Herzen and Sclater were part of a team that detected strange warm-water plumes at the Galapagos Rise — evidence of hydrothermal vents caused when water interacts with heated rocks.
In 1977, after Von Herzen and colleagues returned to explore these strange vents with remote-controlled submersibles, they found evidence of diverse communities of sea life, including enormous clams, white crabs and red-tipped tube worms.
The ecosystem, in a high-pressure environment far beyond the reach of light, could not rely on photosynthesis; instead, the microbes at the base of the food web performed chemosynthesis, generating energy through chemical reactions.
This and subsequent discoveries by other researchers "basically opened up a whole new field of science," said Keir Becker, a marine geophysicist at the University of Miami who spent about seven months on seven different scientific expeditions with Von Herzen.
Throughout his career, Von Herzen developed new tools and techniques that allowed researchers to measure the heat coming out of the ocean floor from the earth's molten interior.
"Dick was always an engineer and tinkerer at heart," said Carolyn Ruppel, a research geophysicist with the U.S. Geological Survey at Woods Hole who worked with Von Herzen in the 1990s.
In 1998, the American Geophysical Union awarded Von Herzen the Maurice Ewing Medal in recognition of his contributions to the field.
Von Herzen was born May 21, 1930, in Hollywood, the eldest of six children. His father, Constantine, was a lawyer and his mother, the former Elizabeth Hevener, was a schoolteacher.
His grandfather, Frank Hevener, served as mayor of Laguna Beach, and Von Herzen spent much of his childhood by the ocean, learning to swim, surf and sail. At work he went on ocean expeditions, and off work he scuba dived and taught his children to sail.
"It seemed as though, if it were possible, he was in the ocean or on the ocean his entire life," his daughter Lane said.
After graduating from Caltech in 1952 with a bachelor's in geophysics, he served in the U.S. Army from 1953 to 1955. He earned a master's degree in geological sciences at Harvard in 1956 and a doctorate in marine geophysics in 1960 at the Scripps Institution, which is part of UC San Diego.
He went on his most recent diving trip at age 82, his daughter said.
Lane Von Herzen said she recently found a bucket list written by her father with five entries: the West African mountains, the Amazon, the Andes, Cabo Pulmo in Baja California Sur — and snorkeling with whale sharks.
"These are all the adventures he wanted to have," she said.
He is survived by his daughter and son Brian; two grandsons; his brothers Norman, Michael and Jim; and his sister Joyce. He was preceded in death by his wife of 54 years, Janice, who died in 2012, and his brother Bruce.