The highest tides of the year will be rolling in this weekend with the holidays. Known as king tides, the natural phenomenon occurs when a new or full moon coincides with the moon reaching its closest point to earth in its elliptical orbit, resulting in a stronger gravitational pull than usual and causing higher than normal tides.
This year’s king tides will peak along the California coast on Dec. 23 and 24 during which time residents can expect to notice about a several foot increase from average high tides, with a predicted high tide of 7.1 feet above mean sea level.
While king tides are a normal and natural phenomenon, a spokesperson for the California Coastal Commission said in a statement that they "provide a glimpse of what to expect as sea levels rise" due to the unnatural and human-caused effects of climate change.
"King tides are one to two feet higher than an average high tide, which is approximately what daily tides will be in the next few decades due to human-caused sea level rise," the statement said.
The Coastal Commission said they hope the king tides will bring more attention to climate change, the resulting sea level rise and its causes.
"Sea level rise is caused by burning fossil fuels like oil, gas, and coal, which releases carbon dioxide and other gasses into the atmosphere," it said. "These gasses act like a blanket, trapping in heat that would otherwise escape, raising the global temperature of the land, air, and ocean."
This causes glaciers and ice sheets to melt into the ocean and warming temperatures cause water to expand in volume. While this is a process that is already underway, the Commission said the extent to which sea level will continue to rise depends on human activity.
"The ultimate amount of sea level rise will depend on the speed of transition to non-fossil fuel energy sources," it said.
To help scientists study and prepare for the future, the Coastal Commission launched an initiative in 2018 to document high tide levels through community-sourced photos. Referred to as the California King Tides Project, each year, individuals living in king-tide affected areas are asked to photograph the shoreline.
"The December King Tides will coincide with good weather, offering a safe opportunity for folks to witness and document this natural phenomenon, as long as folks keep their eyes on the water so they aren’t surprised by any rogue waves" Heal the Bay Water Quality Scientist Annelisa Ehert Moe said.
According to the recent predictions from the National Oceanic and Atmospheric Administration (NOAA) sea level is on track to rise an average of 10-12 inches along US coastlines by 2050.
"Photographing these extreme high tides brings attention to the impact of climate change and helps California plan for a future when today’s king tide is an everyday occurrence," the commission said.
Moe added that the high tides will provide "a clear snapshot of what the regular daily high tides will likely be by 2100, even with minimal sea level rise."
Santa Monica Beaches are wide, meaning the tides will be less noticeable than on narrower beaches in neighboring locations such as Malibu.
A spokesperson for the LA County Department of Beaches and Harbors said that crews will be monitoring the impacts of the tides, especially erosion at Venice Beach Will Rogers State Beach.
King tides are expected to hit California shores again early in the new year on Jan. 21 and 22 and Moe said Heal the Bay will be participating in several "group science events" with other organizations including one at the Santa Monica Pier with Climate Action Santa Monica.
"We should have safe conditions, so Heal the Bay will be out celebrating this global, astronomical event during the January phenomenon," she said.
