It’s been a very busy three days (and nights). The tsunami is still ringing in Crescent Harbor – amplitudes are about 20% of the peak and below hazard levels but still too high to safely work in the harbor or send in divers to assess the situation beneath the water. There is a diesel spill and other hazmat concerns. Ten boats sank – 9 of them deposited in the boat basin and one sailboat swept out into the larger harbor and deposited near the mouth of Elk Creek. Some accounts mention 11 sunk boats – but that counts one that sank about 7 years ago. Most of these boats were derelict or little used. There are concerns that some of the rock bank failed and sediments were deposited on the basin floor. We won’t know the full impacts until an underwater assessment can be completed. All of the damage appears confined to the boat basin – I have yet to hear of any significant problems in the inner or outer harbor. I don’t have the exact count of the boats that put to sea before the tsunami arrived – it seems to be in the neighborhood of 25. The process of notification of boat owners began late Thursday evening and seems to have gone well. The evacuation was orderly. This event points out the importance of tsunami plans at all ports and harbors, even small ones like Crescent City and Brookings. While leaving the harbor seems to have gone smoothly, not all captains were prepared for the long offshore wait or had sufficient fuel to make it to alternate port. As Friday afternoon wore on, concerns grew about when the boats could come back to port and where they could dock. The closest undamaged facility was in Humboldt Bay but several boats couldn’t make it that far. There was also concern about a storm due to arrive late Friday evening. Humboldt Bay has one of the most hazardous entrances of any West Coast port and smaller boats can only safely enter on flood tides. So the decision had to be made to allow boats back into the ports while the advisory was still in effect. The boats with insufficient fuel returned to Crescent City. They docked at the south side of the outer harbor where the currents were not as strong. Most of the Crescent City fleet along with a number of boats from Brookings went to Humboldt – we observed a steady stream of boats crossing through the mouth from about 6 PM to midnight.
I’ve only document one instance of overland flow in Del Norte County. Tsunami amplitudes just before High High tide a little after 3 AM Saturday morning reached a little over a meter and caused the highest water stand (about 2.8 meters above MLLW) of the whole event. Deputy Sheriffs observed water “boiling onto the roadway” at the campground near Elk Creek. They will provide me with a detailed high water line when I return tomorrow. This highest water stand occurred around the 40th cycle and 20 hours after the first wave arrival. The effect of the ambient tide was huge in this event. Had the tsunami occurred 6 hours earlier or 18 hours later, major on-land flooding would have occurred.
