Interview with Carlos Neves, oceanographer and researcher at CIMARQ UNAB about the strong swells in the country

Natalia Cabrera, UNAB Journalist.- Carlos Neves, oceanographer and researcher of Quintay Marine Research Center (CIMARQ) of the UNAB Vina del Mar Headquarters was interviewed by Chile due to strong seas, with waves that exceed six meters, which were recorded on Tuesday, June 6, 2023 on the beaches of the Ñuble Region, product of the frontal system. Cobquecura and Coelemu were just some of the areas affected by the harshness of the strong winds and storm surge.

“The main generating effect of storm surges is the wind in the open ocean. The open ocean facing persistent wind conditions in space and time. And this energy propagates from the open ocean to the coast, finding these conditions where there are breaking waves that rise above the normal water level”, explained the oceanographer.

Likewise, the professor explained another phenomenon that influences these cases. The tide, as is well known, is the change in sea level produced by the gravitational attraction exerted by the sun and the moon. These two forces, which pull each one to its side, generally do not coincide, except about twice a month, which is when they align with the Earth in the same line. When this happens, the gravitational forces that they exert on the sea add up completely, causing the highest levels of high tide or high tide. This species of recharged high tide receives the name of syzygian tide.

Storm surge is different from a tsunami. A tsunami faces the entire volume of water produced, let’s say, by a generation, which can be a terrestrial earthquake or a submarine earthquake, or the fall of a glacier detachment or the detachment of a clearing near the coast or even the fall of a meteorite, therefore, they are different waves. The tidal wave is different from a tsumani and its energy conditions are also different. In the case that we have seen these days, the syzygy condition is what has caused it to overflow beyond the normal condition of sea level. Like what happened in the Ñuble Region, Neves pointed out.

The professor also specified how the coast faces the direction of the wind: “We have bays that are generally open to the north, so they are protected from storm surge events from the south, but not from the conditions of storm surges that come from the north where they arrive straight towards the coast. Most of our bays are open to the north and protected to the south”. Finally, the academic was consulted about the phenomenon of the “Niño” and the tidal waves.

Review the full interview on Chile on June 8, 2023