The Next Tsunami

Not until the late 1990s could scientists fix the date, hour, and magnitude of the Pacific Northwest coast’s last megathrust earthquake: 9 p.m., January 26, 1700, magnitude 9.0—one of the largest quakes the world has known. When the next one strikes the tsunami it generates is likely to be the most devastating natural disaster in the history of the US.

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On a March evening in 1964, ten-year-old Tom Horning awoke near midnight to find his yard transformed. A tsunami triggered by Alaska’s momentous Good Friday earthquake had wreaked havoc in his Seaside, Oregon, neighborhood. It was, as far as anyone knew, the Pacific Northwest coast’s first-ever tsunami.

More than twenty years passed before geologists discovered that it was neither Seaside’s first nor worst tsunami. In fact, massive tsunamis strike the Pacific coast every few hundred years, triggered not by distant temblors but by huge quakes less than one hundred miles off the Northwest coast. Not until the late 1990s would scientists use evidence like tree rings and centuries-old warehouse records from Japan to fix the date, hour, and magnitude of the Pacific Northwest coast’s last megathrust earthquake: 9 p.m., January 26, 1700, magnitude 9.0—one of the largest quakes the world has known. When the next one strikes—this year or hundreds of years from now—the tsunami it generates is likely to be the most devastating natural disaster in the history of the United States.

In The Next Tsunami, Bonnie Henderson shares the stories of scientists like meteorologist Alfred Wegener, who formulated his theory of continental drift while gazing at ice floes calving from Greenland glaciers, and geologist Brian Atwater, who paddled his dented aluminum canoe up muddy coastal streams looking for layers of peat sandwiched among sand and silt. The story begins and ends with Tom Horning, who grew up to be a geologist and return to his family home at the mouth of the river in Seaside—arguably the Northwest community with the most to lose from what scientist Atwater predicts will be an “apocalyptic” disaster. No one in Seaside understands earthquake and tsunami science—and the politics and complicated psychology of living in a tsunami zone—better than Horning.

Henderson’s compelling story of how scientists came to understand the Cascadia Subduction Zone and how ordinary people cope with that knowledge is essential reading for anyone interested in the charged intersection of science, human nature, and public policy.