Friday, March 11, 2011

Santa Cruz and the Tsunami of 2011

Around 8:20. Notice the black mast on the
Express 37 which is leaning to the right,
having gone aground due to the low "tide".
I heard about the Japanese 8.9 earthquake shortly before turning in on 3/10/11 and wondered if a major earthquake in Japan could threaten the California coast. I remembered back to Easter weekend when I was nine years old, being awakened by my father who said we were under "mandatory evacuation". A major earthquake had hit Anchorage, Alaska, and most of the California coast was being asked to evacute prior to the antcipated tsunami. It was around 10:00 at night when we got out of bed, loaded the family into the car, and left sea level at Rio del Mar, and headed for higher ground. 
Fast forward to this morning. The news from Japan was grim: hundreds dead, a nuclear power plant threatening to release radiation, and a tsunami headed this way which had already inundated Japan but had done little damage in Hawaii. California was next, and the tsunami was predicted to arrive at 7:40am. Or was it 8:08am? Was Monterey going to be devastated, or Moss Landing, or Santa Cruz? Would Crescent City Harbor be destroyed, as it was in 1964, or would it be spared due to the different direction of the wave?
Morning at the Harbor

It's always hard to capture current in a still image, but the
speed of the current in the channel could have reached
10 knots.
At 7:40am, I drove the few blocks to the harbor. It was difficult to believe that anything of significance was going to transpire. There were perhaps 30 people lining the Murray St. bridge and looking out to sea, which was a little ominous, but the weather was calm, the sun was out,  and other than a few "Road Closed" signs, the harbor looked like it belonged to the Pacific (Peaceful) Ocean. I parked on Lake Ave. near the Kayak Connection and drank my coffee while waiting for what I suspected would be a non-event. Some commercial fishermen were on the wharf below me, nervously waiting for whatever was going to happen. Bill Lee, local boatbuilder/naval architect and Port Commissioner, wandered over and chatted with me about what we thought was about to happen. At 8:07am, I noticed that the far side of the harbor was indicating a tide of about 2.5 feet. You can figure out the height of the tide in Santa Cruz by realizing that the west side sea wall goes "under" at 6' of tide. As Bill and I watched, the freeboard of the seawall quickly diminished, until only a foot or so was showing. My guess is that the first wave into the harbor brought in 3' of water in a few minutes. While we could determine some current flowing north into the upper harbor, we had very little sensation of lots of water rushing in and out (that was to happen shortly thereafter.)

The dredge Seabright, around 8:30am. The steel dredge pipe
has capsised, and the dredge has dragged one or more
anchors. Each anchor weighs 750 lb.
To get a better perspective of the waves and water flow into the harbor, Bill and I drove down Lake Ave. to the harbor office. We walked over to the fuel dock, but were encouraged by the harbor police to get to higher ground. That seemed to set a pattern for the day; it was never clear just where you could go and where you couldn't.
From the second floor vantage point of the O'Neill building, it was obvious that a tremendous amount of water had ebbed from the harbor, creating a large, dirty swirl of water on the calm surface of Monterey Bay. The harbor dredge "Seabright" had dragged one or two of her five anchors, and was apparently heading out of the mouth of the harbor towards Monterey. Her steel dredge pipe had capsized, creating a hazard to navigation for anyone who tried to pass between the steel floats that would normally support the pipe.

Looking south out to sea, a large muddy eddy formed from
the water that had until recently been in the harbor.
Bill and I tried to estimate the speed of the water flow as it ripped by the Crow's Nest, gas dock, and Aldo's on the west side of the harbor. I think it's very possible that the current hit ten knots at times. After a while the current would start to diminish, and you could see the start of a flood current on one side of the channel or the other. It was sort of like looking at the Bay Model in Sausalito, where you can start to figure out why it can be flooding along the Cityfront in San Francisco, while it ebbs under the Golden Gate.

After U1-Dock had broken apart, only the pilings and a few
hardy boats were left. Many were pushed up-harbor to the
next finder of U1-Dock, while others were on the bottom.
Note the current; this was taken around 2:00pm.
Slack water was, inevitably, followed by a current reversal and a gradual acceleration of the speed of the current until it was flowing at full speed into the harbor. From slack water to full flood to slack water to full ebb to slack probably took 25 minutes or so.
While the deck of the O'Neill building provided a clear view of the mouth of the harbor, we were unaware of the damage that was unfolding in the area around the Murray St. bridge and the upper harbor. Rather than reach a gentle equilibrium as the water flowed into the upper harbor, it began to back up against the far reaches of the harbor, causing boats and docks to be twisted and jostled around. At one point, the UCSC floating kayak docks was torn free and began to travel up and down the channel with each current reversal. Loaded on top of the dock were dozens of kayaks and rowing shells, pieces of which littered the edges of the harbor on the following day.

For a map of the harbor, click here.

From what I can remember, the Anchorage earthquake in 1964 caused two big waves to travel down the California Coast. Santa Cruz Small craft harbor, which had been finished only recently, was generally undamaged, and Rio Del Mar beach suffered no damage where my family's beach house was located. The water receded hundreds of feet from it's normal height, then returned, then receded, then returned, and that was that.

Boats that were sideways to the current created additional
strain on the pilings and docks. This shot is from the
Murray St.bridge looking toward Aquarius Boat Works.
The tsunami caused by the 2011 Japanese earthquake was dramatically different in that it continued to cause current reversals for the entire day and into the night and the following day. About ever half hour, another cycle would start as the harbor would quickly fill up with water, then pause, and them empty back into Monterey Bay. Some cycles were more dramatic than others, but just when you thought that you'd seen the last one, it would start up again. The current reversals began working on the increasingly weak docks and dock lines and pilings, and the entire harbor, but specifically the docks near Aquarius Boat Works and U1 began coming apart.

Pilings began to tear through the docks
as the current ebbed and flowed.

Around 10:00am, two waves entered the harbor and began ripping northward. There are several good videos of the waves, some taken by amateurs and one which appeared on Fox News. They are dramatic, and you will wonder how any boat, or any dock, in the upper harbor survived. However, the next day, that section of dock looked remarkably intact, perhaps due to it's relatively new construction and plastic buidling materials.
This is the best overall video, which shows that there was more than one wave.
Video #2, taken approximately 100 yards north of the Murray St. bridge, west side.
Video #3, taken approximately 300 years north of the Murrat St. bridge, west side.

You'll undoubtedly be able to see more amateur videos on YouTube in the coming days.

Southern Pacific railroad trestle over the mid-point of the
harbor. Built in 1967, it replaced an old wooden trestle
when the upper harbor was constructed.
As the day unfolded, more and more interested residents began arriving at the harbor. The Murray St.  and the Southern Pacific railroad bridges became ideal places to see the mayhem in the lower and upper harbors. Suspended 20-30 feet above the water's surface, the bridges allowed people to see the event unfold without being told to move and without fear of injury or drowning.

Alan's Monterey Bay 30 around 3:00 in the afternoon.
U1-Dock began to disintegrate around mid-morning. The current appeared to be especially fast, perhaps due to the narrow channel in the vicinity, or possibly due to the turn that the harbor takes at that point. Some boat owners, seeing the deterioration of the docks, offered to move their boats but were turned down by members of the harbor patrol. One of the casualties was a Monterey Bay 30 owned by Alan Wirtenen, which ended up capsizing and being dragged by the current into the lower harbor, where it was finally lassoed and tied up near the launch ramp.


To add insult to injury, this portion of G-Dock ended up
on top of this center cockpit sailboat. This same boat is visible
in the videos that are linked to above.
The day after the Santa Cruz Tsunami dawned bright and clear. Over a hundred harbor locals showed up at the Santa Cruz Yacht Club for a memorial for Joel Verutti, a Moore 24 sailor and wonderful father and husband. The harbor had a subdued buzz as people walked along the shores, checking in on friend's boats, and wondering how an event 5,000 miles away could create such a mess in our lovely harbor.

This poor Santana 22 sank in her slip. Efforts were being madethe next day to raise her and allow her to sail again.

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