Moon oscillation will intensify flooding along U.S. coast by mid-1930s, research finds

Recurrent high tide flooding is expected to worsen as the sea level continues to rise due to climate change, but, as a new study warns, a regular 18.6-year cycle involving the Moon could trigger unprecedented flooding along America’s coasts in the 2030s.

Noxious flooding, good-weather flooding, or flooding at high tide, it’s the same thing, and it’s an annoying pain in the ass. In 2019, NOAA tracked more than 600 of these recurrent flooding at high tide, in which the high tides are 2 feet (0.6 meters) above the norm. These floods are not life threatening, but they can damage coastal infrastructure in affected areas and create inconveniences such as flooded parking lots. Needless to say, harmful flooding is happening more often due to human-induced climate change, and it’s about to get worse as sea levels continue to rise.

If that’s not enough, an 18.6-year lunar cycle should amplify this effect even more, according to news research published in Nature Climate Change. The authors of the article, led by Phil Thompson of the University of Hawaii, claim that the confluence of sea level rise and a periodic oscillation of the orbit of the Moon will increase the frequency and severity of high tide flooding along the US ocean coasts. By the mid-1930s, tidal flooding could occur in batches that last a month or more and almost daily, scientists say. Members of the NASA Sea Level Change Science Team at the University of Hawaii contributed to this research.

Scientists have known about this oscillation of the Moon’s orbit since the early 18th century, as well as how alignments involving the Moon, Earth, and Sun can influence the tides. During the first half of this cycle, high tides are below normal average and low tides are above normal. During the other half of the cycle, high and low tides are amplified, appearing both higher and lower than usual. The reason is related to the gravitational pull of the Moon, which causes the oceanic tides of the Earth. We are currently in the amplification phase of this cycle, but the gravity of the Moon is not affecting the tides to the degree expected in the mid-2030s when the amplification phase renews itself.

All of this is well known, but scientists now need to predict the effect of this lunar cycle in the age of climate change and sea level rise. Indeed, the situation looks bad, Moon falters or not. Figures provided by NOAA paint a grim picture, with estimates suggesting that global sea level will rise by at least 12 inches (0.3 meters) by the end of the century. Unfortunately, the world is currently on the right track for worst case scenario of sea level rise that scientists modeled and that researchers discovered more and more worrying signs regarding Antarctic ice. In 2014, nearly 40% of the American population inhabits coastal areas that may be vulnerable to sea level rise.

“Low areas near sea level are increasingly threatened and are suffering due to increased flooding, and this will only get worse,” NASA Administrator Bill Nelson said in a statement. communicated. declaration. “The combination of the Moon’s gravitational pull, sea level rise and climate change will continue to exacerbate coastal flooding on our coasts and around the world.”

To build the new predictive model, Thompson and his colleagues studied tidal information collected by 90 gauges spread along the U.S. coastline, statistics on flooding at high tide, and weather events such as El Niño events, cycles astronomical, among other data points. Recurrent high tide flooding is expected to occur more often along nearly all of the mainland coasts of the United States, Hawaii and Guam. Alaska will not experience these problems for at least a decade or more, as its landmasses are actually increasing due to geological processes.

Thompson said high tide flooding is not as severe as hurricane storm surges, but warned of cumulative effects and also the emergence of “seepage sumps” as a public health problem. . City planners should take notice of the new findings and act on them, the scientists in the study conclude.

After: Rising sea levels alone threaten to crush the global economy.