While several parts of the capital city flooded this weekend, no injuries or major damage was reported. Government workers used heavy equipment to clear rocks, coral and other debris that washed onto roads, making vehicle passage hazardous.
Flooding of these small islands — many of which rise less than one meter above sea level — will increase in “frequency and magnitude” in the coming years, said marine researcher Dr. Murray Ford on Saturday.
Ford, a University of Hawaii Sea Grant extension agent working at the College of the Marshall Islands in Majuro studying sea level rise, said Saturday’s high tide of five and a half feet was exacerbated by the weather phenomenon known as “La Niña” that has caused the base sea level to rise by six inches in recent months.
This weekend’s tides are not unusual — they are a predicted annual occurrence.
“However, as the sea level is temporarily higher as a result of La Niña and overlies long-term sea level rise, the impacts are magnified,” Ford said.
“While these events happen only a handful of times a year at present they will continue to increase in both frequency and magnitude.”
Majuro and two remote islands, Namdrik and Kili, experienced inundation of low areas during the highest tides at the end of January.
“Right now, sea level data coming off a tide gauge (located in Majuro to record data for long-term sea level changes) is indicating that average sea level is more than six inches above predicted,” Ford said. Last year’s El Niño caused lower than average sea levels, while the current La Niña typically results in higher sea level in the western Pacific, he said.
“The potential inundation of both ocean and lagoon facing shorelines is a function not only of the tide level but also the incident wave conditions,” Ford said. “Large swells can drive inundation on both the ocean and lagoon coast.”
On Majuro, there are few islands that are wider than 75 meters.
Overcrowded conditions in the urban center have forced people to build homes within a couple of meters of the shore, increasing their exposure to flooding during peak tide periods.
A University of Hawaii project is examining wave driven inundation around Majuro, Ford said. The work is in progress but is already shedding some light on wave processes on the reef adjacent to the college, Ford said.
“The January spring tide coincided with some swell generated into the north Pacific,” he said. “This caused widespread inundation on Kili Island.
Water inundated large sections of the island and was over knee deep in many areas. A significant amount of undergrowth has already died and turned brown as a result.”
