A study conducted by scientists from the University of California Santa Barbara along with their associates from various different institutions reveals that the 2015-2016 Winter had one of the strongest El Niño weather events in the last 145 years. While residents living in Southern California may remember the winter of 2015-16 as somewhat unforgettable, there is actually a more dangerous issue behind it.
According to the study, there was a significant increase in the winter beach erosion on the California coast as it becomes 76 beyond the level of normal. In fact, scientists have also discovered that most beaches found in California have eroded beyond historical extremes.
The authors of the study had investigated 29 beaches from Washington to California, approximately 2000 kilometers of the West Coast. They have had to make 3-D surface maps, GPS topographic surveys, and cross-shore profiles through the use of airborne LIDAR (light detection and ranging), an aerial remote sensing method used for examining the earth's surface. According to the National Science Foundation, they also collected direct sand level measurements along with the wave and water level data for each beach surveyed from 1997-2016.
While it can be said that winter beach erosion, where sand is removed from the beach, is a naturally occurring seasonal process, during El Niño events it can get quite severe. The 2015-16 El Niño, as well as the El Niño winters of 1982-83 and 1997-97, are considered to be the three strongest El Niños ever recorded. Luckily, though, while there are beaches that had eroded to historical extremes, there are still some beaches in California that weren't as affected as the others, the US Geological Survey reports. David Hubbard, a marine ecologist at UC Santa Barbara and co-author of the study explains why. "The severity of the erosion as well as the beaches' ability to recover from the process is also highly depended on the beaches' condition before the winter of 2015," he explains.
Even with the extensive dam constructions brought upon by the 20th century, rivers are still the California beaches' primary source of sand. However, since California is still in a continuous state of drought, the river flows much lower than usual resulting to even less sand getting carried into the coasts. The full study has been published in Nature Communications.
