The California Coastal Commission is encouraging beachgoers to help document this winter’s king tides in an effort to help scientists and public officials visualize what the coastline could look like with sea-level rise.
King tides, which are typically considered some of the highest tides of the year, occur when the moon, earth and sun are aligned — specifically during a perigee, or when the moon is closest to the earth during a new or full moon.
These perigean events result in larger tides and typically happen three to four times a year. While they bring large waves crashing against seawalls, they can also bring especially low tides — ideal for spotting critters in tidepools.
This year’s king tides came to San Diego in early November and will return again Dec. 4, 5 and 6 and Jan. 2 and 3.
The California Coastal Commission is asking people to photograph the high tidal waters and the impact of the waves and submit their photos to the California King Tides Project.
The agency suggests taking photos in areas that are subject to flooding and erosion and in places where the magnitude of the high waters can be viewed, such as along cliffs and sea walls, piers and staircases.
Scientists say that king tides can give the public an idea of the flood and erosion risks in coastal areas as sea levels continue to rise with climate change. The sea level’s global average has risen 8 to 9 inches since 1880, according to the National Oceanic and Atmospheric Administration.
In California, it’s expected to rise as much as 1.2 feet by 2050. King tides will typically raise the tide about a foot higher than the average high tide, making these tides a helpful visual portrait of the coast’s future.
In San Diego, scientists measure tides with gauges located in Imperial Beach, National City, the Broadway Pier, Quivira Basin in Mission Bay and in La Jolla.
This December, the first high tides are expected to reach San Diego’s coast in La Jolla at 7:34 a.m. on Dec. 4, reaching 7.06 feet.
The tide gauge in National City predicts tides will be 7.82 feet at 8:28 a.m. on Dec. 5 — the highest tide prediction in San Diego.
King tide predictions for San Diego and all of California can be found through the Coastal Commission’s King Tides Project.
Low tides will come in about seven hours after the high tides peak. At this time, San Diegans can explore tidepools or parts of the beach that are typically underwater.
The commission encourages beachgoers to exercise caution when they’re at the coast taking photos.
Be mindful of slippery rocks and large waves. Avoid turning away from the ocean so you can keep an eye on its movements. Shore birds may also be in areas above the tideline, so be respectful of the animals when visiting.