Of all the hazards that hurricanes bring, storm surge is the greatest threat to life and property along the coast. It could sweep homes off their foundations, flood riverside communities miles inland, and collapse sand dunes and levees that normally protect coastal areas from storms.
When a hurricane reaches the coast, it pushes huge amounts of ocean water onto the beach. This is what we call storm surge.
These surges appear as a gradual rise in water levels as the storm approaches. Depending on the size and path of the hurricane, storm surge flooding can last for several hours. After the storm passes, we retreat.
During a hurricane, water levels can rise more than 20 feet above normal sea level. When topped by powerful waves, a hurricane’s storm surge can cause catastrophic damage.
What determines how high storm surges occur?
Storm surge begins in the open ocean. The strong winds of a hurricane push ocean water around, causing water to build up during the storm. The storm’s low pressure also plays a small role in raising water levels. The height and extent of these water piles vary depending on the strength and size of the hurricane.
As these water piles move toward the coast, other factors can cause them to change in height and extent.
that depth of the sea floor It is one factor.
If a coastal area has a seafloor that slopes gently away from the coastline, it is more likely to experience storm surges than areas with steeper slopes. The gently sloping terrain along the Louisiana and Texas coasts contributed to some of the destructive storm surge. As Hurricane Katrina surged in 2005, levees failed and New Orleans was flooded. Hurricane Ike’s 15-17 foot storm soar In 2008, waves swept away hundreds of homes on Texas’ Bolivar Peninsula. Both were large, powerful storms that hit vulnerable areas.
The shape of the coastline can also form surges. When storm surge enters a bay or river, the topography of the land can act as a funnel, sending the water higher.
Other Factors That Shape Storm Surge
Ocean tides caused by the gravitational pull of the moon and sun can also strengthen or weaken the effects of storm surges. Therefore, it is important to know the timing of local tides compared to hurricane landfall.
At high tide, the water level has already risen. If landfall occurs during high tide, the storm surge will cause water levels to rise further and more water to flow inland. The Carolinas saw such impacts when Hurricane Isaias struck near high tide on August 3, 2020. Isaias is about 4 feet in Myrtle BeachSouth Carolina, but the water level 10 or more feet Above normal.
How storm surges and high tides cause coastal flooding. COMET Program/UCAR and National Weather Service
sea level rise Storm surge impacts are another concern.
As the water warms, it expandsAnd that has slowly caused sea levels to rise over the past century. Earth’s temperature has risen. Melting ice sheets and glaciers also add to freshwater sea level rise. together they raise the background sea level. When a hurricane arrives, higher seas mean storm surge can bring water further inland, causing more dangerous and far-reaching impacts.
Anthony C. Deidrake Jr. He is an assistant professor of meteorology at Penn State. This article is republished from: conversation below Creative Commons License. read original article.
