'King tides' may provide glimpse of future
The state Department of Ecology is asking people to photograph high tides to provide a benchmark for study as sea levels rise.
While it might seem counter-intuitive, the Earth is actually slightly closer to the sun in winter than in the summer for the northern hemisphere, making for stronger gravitational pull -- and the highest tides of the year.
Tides are forecast to be up to 12 feet above mean sea level or higher through much of this month and into January. Those highs will be balanced by minus tides on the low side much of the time.
There's no objective standard for declaring a "king tide," said Hedia Adelsman, a policy advisor for the state Department of Ecology.
The term likely originated in Australia or New Zealand, according to multiple sources. It just means very high tides, Adelsman said.
"It's not that scientific," she said.
The Earth's rotation around the sun is not circular but elliptical. The Earth's perihelion with the sun -- when it's at its closest point -- usually occurs in early January. Apehelion, when it's at its farthest, is in early July. The difference in distance is about 3 percent.
This month, many of the high tides are during the day with lows at night, which is one reason state officials are publicizing the phenomenon. They're asking people to send photos.
The ecology department has been collecting the photos for three years now and posting them on the Web to demonstrate how it might look if sea levels rise because of climate change.
Recent scientific studies project that global sea level could rise anywhere from 4 inches to 4 feet or more by 2100, depending on location, according to the department.
The photos could be used to shape shoreline policy planning, officials say. Rising water levels could erode shorelines and move beaches inland. Homes, businesses, roads and seawalls could be jeopardized.
The danger is highest during windy, stormy conditions that bring tidal surges. So far this month, king tides have come during a period of cold and calm weather.
Stephanie Clark of Everett and her husband frequently visit the beach in Mukilteo. They didn't know about the tides before they went down on Monday morning, she said. At high tide the water was near the driftwood line.
"I don't think I've ever seen it this high," she said.
The high tides can have a big effect on boaters, said Matt Barron of Everett, a retired tugboat captain who visited the Mukilteo waterfront on Monday. He goes to the beach frequently but knew about the high tides, he said.
"There can be a lot of wood on the water from these tides," he said. "The big tides also come with big currents."
His last job was to dock and undock oil tankers in Valdez, Alaska, Barron said.
In the highest tides, "it was tough to get position right alongside," he said.
Denny Rochford of Mukilteo, a salesman, sometimes takes a tablet and works from his car on the waterfront. The high tides drew him on Monday.
"Just because it's different and interesting," Rochford said.
Since 2010, the Ecology Department has collected nearly 700 king tide photos from the public, Adelsman said.
"If it's very stormy, we also tell people to make sure they're safe," she said.
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Shoot the tide
The state Department of Ecology suggests the following steps for sending "king tide" photos:
•A king tide map and schedule are available at tinyurl.com/EcologyKingTides.
Public beaches may be located with the department's coastal atlas at tinyurl.com/6t6ofea.
Take photos during a king tide, preferably where the high water levels can be gauged against familiar landmarks such as sea walls, jetties, bridge supports or buildings.
Note the date, time and location of your photo, then upload your images on the Washington King Tide Photo Initiative Flickr group at tinyurl.com/FlickrKingTides.
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