PSU Magazine Spring 1999

If it happened again-and one is due any day now, give or take a couple of hundred years-it would wipe out beach-level communities up and down the coast. If you were lucky, you'd have 15 minutes' warn– ing, and with streets in most beach towns running parallel to the ocean, you might have trouble getting away in that amount of time, Peterson notes. That long-ago tsunami may very well have severely undercut the cliffs below Cape Meares, though geolo· gists aren't quite sure about it, says Peterson. True or not, catastrophic events like tsunamis hint at subtler, but still mighty forces that pit ocean against land in a violent, age-old battle. Severe winter storms from the '93 and '97 El Ninos dug a deeper chan– nel close to the Cape Meares beach, allowing waves to break much closer to shore and eat away at the protec– tive, low-level dune shielding the much bigger one above. And that bigger one was not the mature, geologic adult that experts had thought, but an unstable adoles– cent, ready to give way. Meanwhile, driven by the storms, sand was on the move in the 100 littoral cells that bejewel the Oregon and Washington coastline, says Peterson, whose decade of research has focused on the scimitar-shaped beaches. Sand not only migrated from the southern to northern points of the cells, but generally drifted northward all along the coast, some· times with a net loss of beach, as happened at Cape Meares. With pressures to develop along the coast growing every year and the best sites already taken, understand· ing the precarious, ever-changing geology of the coast is more impor· tant than ever, Peterson says. Otherwise, we'll see a lot more dream houses lost to the fury of the sea. D SPRING 1999 PSU MAGAZINE 17