Coastal residents can take part in citizen-science project documenting "king tides"
“King tides” is a non-scientific name for the highest or the lowest tide events in a year. Christine Voss, a research associate at the University of North Carolina’s Institute of Marine Sciences in Morehead City explains.
“So you’re probably aware of spring tides that occur during full moons and new moons. And those tides are even stronger during what’s called perigee. And perigee is when the moon is physically closest to the Earth in its elliptical orbit around the Earth. Therefore, the gravitational pull of the moon and the sun on Earth is greatest in what we call a King Tide”.
The next king tide event begins Wednesday, Nov. 3 and lasts through Tuesday, Nov. 9. During this time, Voss is asking for the public’s help capturing images of any flooding or high water levels that occur.
“We want to document what the citizens are seeing. We have water gauges located throughout the area and the state of North Carolina through its FIMAN network has other gauges and if you’re able to take a photograph by any of those gauges it will allow us to quantify water levels relative to a standard vertical baseline or NAVD-88. And that allows us to use those data for scientific purposes as well”.
The North Carolina King Tides project started in 2015 and is part of an international project. The submitted photos help scientists document the effects of king tides to better understand how coastal communities will be impacted by rising sea levels due to climate change.
“The idea of the program is to take advantage of these predictable events when we know that water levels are going to be extra high and use these opportunities to help everyone visualize and consider what challenges we’re likely to have with future sea level rise as our climate is changing.”
So far this year, king tides have occured in April, May, June, July and October and have caused higher-than-normal water levels in low-lying coastal communities like Beaufort, Morehead City, and in Down East Carteret County.
“It can be a nice sunny day and you’ll see water crossing, coming up over the road edge, coming up through storm drains”.
According to Voss, many communities along our coast are vulnerable to these extreme high tide events because they were settled hundreds of years ago when sea levels were much lower.
“And sea level rise has been gradually increasing since the last Ice Age. But also there’s been an acceleration in rising sea levels quite a bit over the past 150 years, but that’s increased even more, the rate of rise has accelerated over the past 30-40 years”.
Coastal residents can go to the North Carolina King Tides website and download the Coastal Observers app to submit photos.
“The big picture is that we really want North Carolina Coastal citizens to be aware of the water levels in their communities and what is causing or forcing those water levels. And our climate is changing, and if we adapt to rising sea levels, we’ll be able to enjoy our coast for as long as possible with the least amount of harmful impact”.