Climate Change

Capturing King Tides Through Citizen Science

December 13, 2013

You’re driving through Mill Valley along Highway 101, the sky is blue, the drought persists, and it’s still not raining — yet, the water laps at your tires and the asphalt road resembles a shallow creek. It’s the winter king tides in action and that, organizers at the California King Tides Initiative say, is what the future looks like.

King tides are extreme, high tide events that occur biannually, normally around the summer and winter solstices, when the gravitational pull of the sun and moon are in alignment. While the tides are not affected by climate change, they act as an indicator of the way in which sea level rise will affect coastal communities. Hayley Zamel, an organizing partner for the California King Tides Initiative, said winter king tides, particularly when paired with a storm—as was the case in Pacifica last year—offer a realistic look into the climate-changed future.

Since 2010 CKTI has been documenting these extreme tide events through photography. The result is a growing public archive of images that highlight changes in California’s coastal ecosystems and shorelines in a very real way. The photographs—licensed under creative commons—have been used by climate scientists and researchers to visually represent complicated numbers and statistics associated with sea level rise.

“It’s a lot easier to look at a picture than a graph,” Zamel said. “I think it’s compelling to see a photograph of a heavily used area that will soon become inaccessible.”

A parking lot in Sausalito during a king tide even. Photo:  Doug Moody.
A parking lot in Sausalito during a king tide even. Photo: Doug Moody.

For the upcoming winter king tide event, CKTI has developed a Citizen Science Photo Monitoring Program with an interactive map of specific locations—chosen for their relevance to researchers and natural resource planners—accompanied by photographic guidelines for volunteers documenting a tide event. LaRiviere Marsh at Don Edwards National Wildlife Refuge is one such location, with instructions directing photographers to the overlook area south of Newark Slough on the east side of the trail.

Zamel said the photographs will essentially become data, helping researchers ground location-specific climate models. “There’s a lot of value in getting regular documentation of a specific location, as it helps us create a living record of change,” she said.

Local parks and open space areas are also using king tide events as a way of starting a conversation about sea level rise. Sarah Ferner, the education coordinator for the San Francisco Bay National Estuarine Research Reserve, leads king tide interpretive programs at China Camp State Park and Rush Ranch Open Space Preserve. Ferner said the participants at last year’s program were awed by the quiet beauty of the flooded marsh and inspired to take action after witnessing the effect of sea level rise on natural communities.

San Rafael, Gallinas Creek during a king tide. Photo: Sean/CKTI.
San Rafael, Gallinas Creek during a king tide. Photo: Sean/CKTI.

In addition to the Citizen Science Photo Monitoring Program, CKTI encourages participants to continue photographing king tide events in their community. Zamel said they are looking for compelling and exciting photographs, but advised participants to keep a safe distance and avoid dangerous situations.

“What we really want in a picture is clear infrastructure that’s threatened by high water,” she said. “So that in a way we can see, during these king tide events, a snapshot of what the future will look like in 50 years on just an average day.”

This coming weekend, from Friday to Tuesday the Bay Area will experience a series of extreme low and high tides offering the perfect opportunity to beach comb, tide pool and bird watch.

The 2013-2014 winter king tides will occur at the end of December and January (Dec. 30–Jan. 2 and Jan. 29–31.)

CA King Tides Initiative’s image catalog is at To find out more about this year’s project, go to

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