Beach goers in California have long since sought the killer surf and big waves. As the water temperatures continue to rise, even the most expert surfers will have to take caution, as a new study shows waves seem to be growing larger than ever.
A new study, published in the Journal of Geophysical Research: Oceans, finds that average winter wave heights have grown by as much as a foot in the last 50 years.
California waves were already gigantic. The largest break in California is said to be at Half Moon Bay, with waves cascading as high as 60 feet, and waves 20-30 feet common. The largest wave measured off California as of 2019 is 75 feet tall, more than enough to be labeled ‘extreme.’
Peter Bromirski, a scientist with the Scripps Institution of Oceanography at the University of California, San Diego, found waves are getting bigger and showing up more often year by year.
He discovered that waves produce seismic signals when they hit the shoreline. This allowed him to study seismic records to estimate and measure wave sizes over time for the first time.
He had to ask, so why are they getting bigger? Looking back at records from UC Berkeley dating all the way back to 1930, he found larger waves increased around 1970, when global warming accelerated. It’s not that big waves didn’t exist before that, but smaller waves were more consistent. Big waves were still around but were less extreme and appeared less often than now.
According to a recent report by the Ocean Protection Council, sea level along the U.S. coastline is projected to rise, on average, 10-12 inches in the next 30 years, which will be as much or more as the rise measured over the last 100 years. Since 1880, the global sea level rose approximately 8-9 inches, and the speed that it’s rising is ever increasing.
The higher the sea, the bigger impact the large waves will have on residents.
“If Pacific storms and the waves they produce keep intensifying as climate change progresses and sea-level rises, it creates a new dimension that needs to be considered in terms of trying to anticipate coastal impacts in California,” Bromirski said.
