OXFORD — A wobble with the moon and the lunar cycle could cause “rapidly increasing high-tide floods” on “every U.S. coast”, according to a study from NASA and the University of Hawaii.
The NASA report said changes with the lunar cycle are expected to magnify rising high-tide levels from climate change resulting in a big increase in flooding in the mid-2030s.
Rising sea levels and flooding are already a challenge on the Eastern Shore — including in parts of Talbot and Dorchester counties.
In the mid-2030s, every U.S. coast will experience rapidly increasing high-tide floods, when a lunar cycle will amplify rising sea levels caused by climate change, according to NASA and the University of Hawaii.
The National Oceanic and Atmospheric Administration (NOAA) reported a total of more than 600 such floods in 2019. Those types of floods are projected to increase significantly, according to the U.S. government agency's study
“The floods will sometimes occur in clusters lasting a month or longer, depending on the positions of the Moon, Earth, and the Sun. When the Moon and Earth line up in specific ways with each other and the Sun, the resulting gravitational pull and the ocean’s corresponding response may leave city dwellers coping with floods every day or two," according to the study
The lunar cycle and the moon’s gravitational pull impact tides.
According to the NASA study, “the main reason is a regular wobble in the Moon’s orbit that takes 18.6 years to complete. There’s nothing new or dangerous about the wobble; it was first reported in 1728. What’s new is how one of the wobble’s effects on the Moon’s gravitational pull – the main cause of Earth’s tides – will combine with rising sea levels resulting from the planet’s warming.”
The space agency explains the impacts of the lunar cycle on tides and why they are expected to cause more coastal flooding — including on the Atlantic coast and Delmarva Peninsula.
“In half of the Moon’s 18.6-year cycle, Earth’s regular daily tides are suppressed: High tides are lower than normal, and low tides are higher than normal. In the other half of the cycle, tides are amplified: High tides get higher, and low tides get lower. Global sea level rise pushes high tides in only one direction – higher,” the U.S. agency and university said.
Increased flooding can also damage and impact businesses and residences and can have public health impacts via cesspools, according to Phil Thompson, an assistant professor at the University of Hawaii and the lead author of the new study, published this month in Nature Climate Change.