When will the moon wobble?
The moon is currently in the tide-amplifying part of its 18.6-year wobble, in 2021. But most U.S. coastlines have not yet seen enough sea-level rise to notice the flooding effects. NBC 10 PhiladelphiaMoon ‘Wobble' in 2030s Will Increase High Tide Flooding in NJ, Del. Shore Towns
Researchers predict there could be a “rapid” increase in the frequency of flooding at high tide along coastal regions, according to a report published in the Nature Climate Change journal, produced by the NASA Sea Level Change Team at the University of Hawaii.
The report cites the “wobble” of the moon’s orbit, something that happens regularly every 18.6 years and causes extremely high and low tides, as a factor in potential flooding.
The other factor, according to NASA, involves an increase in global sea level. The study pointed out that higher sea levels have begun to cause some flooding at high tides. The combination of the moon’s wobble and the higher sea level will push high tides higher, the study says.
“High tides get higher, and low tides get lower. Global sea-level rise pushes high tides in only one direction — higher. So half of the 18.6-year lunar cycle counteracts the effect of sea-level rise on high tides, and the other half increases the effect,” NASA explains.
NASA Sea Level Change Team leader Ben Hamlington, one of the study’s co-authors, said that flooding is more likely because the factors that are making it happen now will only be worse in the future.
“We’re getting closer and closer to the flooding thresholds or tipping point in these coastal locations,” said Hamlington. “The same variability in the past that didn’t cause flooding is now going to cause flooding.”
The coastal regions of the U.S. mainland will feel the effects of the flooding, the study said, with Alaska’s coast being spared, but only for a period of time.
“The higher seas, amplified by the lunar cycle, will cause a leap in flood numbers on almost all U.S. mainland coastlines, Hawaii, and Guam. Only far northern coastlines, including Alaska’s, will be spared for another decade or longer because these land areas are rising due to long-term geological processes,” NASA said Wednesday.
Water overflowing into coastal communities during high tide is a common occurrence, often considered a nuisance. But a National Oceanic and Atmospheric Administration report published Wednesday noted that the cases of tidal floods are increasing.
The study is the first to take into account all known oceanic and astronomical causes for floods, NASA said.
“Low-lying areas near sea level are increasingly at risk and suffering due to the increased flooding, and it will only get worse,” NASA Administrator Bill Nelson said in the statement.
Read full article at WSB Atlanta
15 July, 2021 - 03:53am
The moon may look like a peaceful neighbor, but scientists are warning that it may be trying to kill us.
Thank the moon’s 18.6-year “wobble” cycle, which has been observed for some 300 years.
When it wobbles one way, the high tides are lower. When it wobbles the other, however, the high tides are even higher, which could be especially destructive as sea levels rise.
“We’re going to have sort of a double-whammy,” National Oceanic and Atmospheric Administration oceanographer William Sweet, one of the study’s authors, told The Washington Post. “It means that coastal communities — unless they adapt and fortify — are likely to expect even greater flooding than they might otherwise.”
NOAA reported 600 floods caused by high tides along the East Coast and Gulf Coast in 2019 alone. The coming wobble could worsen that, leading to “dramatic increases in flood numbers” in coastal cities around the nation.
“We’re getting closer and closer to the flooding thresholds or tipping point in these coastal locations,” NASA Sea Level Change Team leader Ben Hamlington told NPR. “The same variability in the past that didn’t cause flooding is now going to cause flooding.”
There could even be “clusters” of floods, sometimes lasting a month or more, NASA said.
Just one region may escape the threat ― for now.
“Only far northern coastlines, including Alaska’s, will be spared for another decade or longer because these land areas are rising due to long-term geological processes,” NASA said.
Tidal floods involve less water than those caused by major weather events, such as storms, and are often taken less seriously as a result.
“But if it floods 10 or 15 times a month, a business can’t keep operating with its parking lot underwater,” Phil Thompson, an assistant professor at the University of Hawaii and the lead author of the new study, said in a news release. “People lose their jobs because they can’t get to work. Seeping cesspools become a public health issue.”
In response, NASA has created a “Sea Level Portal” to project what could happen in the future, which includes tools to anticipate flooding.