Global images of ‘king tides’ show risk of rising seas
DEPOE BAY, Ore. — Tourists, nature lovers and amateur scientists are whipping out their cameras to document the effects of extreme high tides on shorelines from the United States to New Zealand, and by doing so are helping better predict what rising sea levels will mean for coastal communities around the world.
A network of volunteer photographers fans out around the globe during socalled king tides to capture how high the waterline gets and where the water goes. They then upload the images — many with geolocation data embedded — for use by scientists, policymakers and even city planners as they study and prepare for the effects of climate change. The photos show where flooding occurs on specific roads, or give clues about whether it’s safe to build new housing, for example, near an eroding bluff.
“For us, the king tide offers a look at where the water will be in about 2050, about a foot to a foot and half above normal water levels,” said Skip Stiles, executive director of Wetlands Watch, a nonprofit that helped recruit 700 people to document a king tide in Norfolk, Va., for the first time there in 2017.
The group’s efforts have since grown into a smartphone app that uses crowd sourcing to gather images and pinpoint flooding.
King tides occur about twice a year in coastal areas worldwide when the sun and moon align to enhance the gravitational pull that produces normal, daily tides. These superhigh tides came into sharp focus in January, when one arrived in Oregon on the same day as a major winter storm, creating 15 to 20foot waves and a massive swell.
Flooding from king tides is a preview of how sea level rise will affect coastal communities — and warmer oceans and bigger storms could amplify those changes, said Peter Ruggiero, interim executive director of the Oregon Climate Change Research Institute. Modeling shows Oregon could experience sea level rise of as little as a foot or as great as 6 feet in a worstcase scenario, he said.
In Georgia, coastal communities constantly struggle with flooding from high tides and storms — a phenomenon dubbed “sunny day flooding” in places across the U.S. South. Chatham County, home to the lowlying city of Savannah, uses dozens of sea level sensors to track tides and collect data for future city planning.
“The combination of the sensor data and the photos really helps build out the story — and with that, we hope it will solidify funding decisions better,” said Nick Deffley, Savannah’s director of sustainability.