Cascadia's Fault - Jerry Thompson [79]
The ground heaved and rumbled beneath their feet. Storefront windows began to rattle and ripple and shatter. All of northern California and much of southern Oregon shook as the edge of the continent sheared away from a down-going slab of the ocean floor. The hilly farmland and redwood forests of the Lost Coast and Cape Mendocino rumbled as the earth rolled and bucked. Lower Humboldt County was ground zero in an event that would make seismic history. The date was April 25, 1992.
When they realized what was happening, the citizens of Ferndale began to scream and run in all directions. Mothers grabbed their children, pulling them off sidewalks and into the street to avoid jagged plates of tumbling glass. Some held straw cowboy hats and sombreros above their heads for protection. People in the street began dropping to a crouch, either because it was too hard to keep standing or simply because they didn’t know what else to do. Some fainted or collapsed from fright. Others, cut by glass or grazed by falling cornices and bricks, lay bleeding on the pavement, surrounded by Good Samaritans trying to help. All of this was captured by a television camera crew who had been covering the parade.
Sixty miles (100 km) north in McKinleyville, Professor Lori Dengler of Humboldt State University was getting her family ready for a day of hiking at Patrick’s Point State Park, on the beach a little farther up the coast. “Suddenly the ground started to jiggle a little bit,” she said, “and then it started to jiggle a lot more strongly.” With her very next breath the instincts of a geologist kicked in. “Fortunately by that time I had actually developed a habit of starting to count the duration of an earthquake. It’s a very good habit to get into with—one, two,” she recounted the beats. “And by the time we got up to about seventy-five, I knew that my plans for the day were completely shot. There was no way we were going on a picnic.”
Back in Ferndale the videotape showed piles of splintered gingerbread trim, cornices, and tons of old brick that had crashed to the ground in heaps of rubble and bunting. Thirty-six homes in this Victorian tourist town were seriously damaged. A dozen others twisted off their foundations and collapsed. Forty businesses in a four-block stretch were damaged, putting 80 percent of the town’s economic engine on life support.
Pipes broke, gas mains ruptured, and fires started. In nearby Petrolia, population one hundred, the bay door of the fire hall got jammed during the initial shock and was stuck in the closed position. It took several volunteer firefighters considerable time and effort to pry it open before their pumper could respond to the now out-of-control blazes. The post office, a century-old general store, and a gas station burned to the ground. Landslides and rockfalls blocked roads and railway tracks.
As the main shock died away, Lori Dengler made her way outside to begin the next phase of her research. “I lay down on the driveway so that I could feel all the aftershocks,” she confessed, apparently unfazed by what this must have looked like to the neighbors. “Earthquakes are really quite delightful if you are in a completely safe place. And I have a very open driveway with no big trees around, so I just lay there for about ten minutes, sort of feeling the music of the spheres—quite literally.” She could tell from the duration that the jolt had been at least magnitude 6, possibly higher, and knew it was time to get to work.
Finding the focal point and calculating the strength of the jolt would take several days but a preliminary investigation showed that a nearly horizontal fault began splitting apart six miles (9.5 km) north of Petrolia and seven miles (11 km) underground in a magnitude 7.1 rupture. Little more than twelve hours later, at forty-two minutes past midnight, another quake, magnitude 6.6, centered fifteen miles (24 km) offshore from Cape Mendocino and thirteen miles (21 km) below the surface struck the same general area, causing additional damage. Less than four hours after the second rip