Ocean and lagoon water flooded the lowest lying areas for three straight days throughout the Marshall Islands and the Federated States of Micronesia this past weekend and Monday, causing sparse damage but requiring big cleanups in their wake.
The road by Amata Kabua International Airport in Majuro was halted periodically by incoming waves and reduced to single lane traffic for several hours Sunday and Monday afternoons as heavy equipment operators moved up and down the long roadway clearing rocks and debris that blocked the road from inrushing tidal water. Waves washing over boulder barriers caused flooding on the road 18 inches deep Monday evening before receding.
The flooding, which started Saturday and continued through Monday night, resulted from a combination of ongoing sea level rise, a high tide, and strong winds created by a storm in the vicinity of the Marshall Islands. There was some over wash Tuesday evening, but nothing compared to Sunday and Monday’s inundations.
Sea level rise is a major contributing factor to the flooding in the Marshall Islands and FSM over the past few days, said a New Zealand-based climate researcher. “An event like this would have been relatively innocuous in the 1990s, but sea level is notably higher today than back then,” said Dr. Murray Ford, who is based at Auckland University. “Sea level rise is increasing the frequency and magnitude of these sorts of events.”
Ford, who previously worked at the College of the Marshall Islands and has studied atolls in the RMI extensively, said Monday’s inundation came during “the highest tide of the month at 2.14 meters (seven feet).”
Monday afternoon, the Weather Service Office in Majuro issued a high surf advisory and warned of “possible inundation and marine conditions hazardous for small crafts. Avoid going near reef lines and beaches.”
Weather officials advised local residents to “take necessary actions to protect your properties and avoid flooded roads and shorelines.”
“I would characterize this event as very high tides — but not the highest of the year — which are higher than predicted due to La Niña, occurring at the same time as some moderate offshore wave heights against a backdrop of sea level that continues to rise at Majuro,” said Ford.
“Unfortunately, with steady sea-level rise these flooding events will become more frequent, more widespread, and far more severe,” said Majuro resident and former RMI government Chief Secretary Ben Graham. “We must plan and prepare for this now.”
Meantime, in the FSM local residents were also reporting widespread flooding.
“Government of the Federated States of Micronesia (FSM) has been made aware of extensive saltwater inundation across the nation’s islands as a result of ongoing king tides and storm surges,” said the FSM President’s Office in a statement late Monday. “The government has received numerous requests from citizens asking for support.”
Photographs from many different islands across the FSM showed flooding in and around people’s homes, roads and shorelines. The FSM President’s Office advised its “citizens affected by the ongoing flooding activity … to document the event extensively, both with photographs and in writing. Cataloging the damage and the effects as they occur will assist the state and national government assessments following the event, and expedite the issuance of necessary assistance.”
According to tidal gauge measuring equipment installed Majuro in the early 1990s by the Australian government sea level has been rising an average of 4.8 millimeters annually at Majuro. Mean sea level at Kwajalein in October was very close to an all time record high, said Ford.
No major damage has been reported in Majuro or Ebeye, the two urban centers. On Ebeye, Monday’s high tide pushed water onto sidewalks and “gushed up” over the dock and shoreline protection, said Hilary Hosia, an Ebeye resident.
The Hawaii-based, US government-funded Pacific Islands Ocean Observing System (PacIOOS) website forecasts tides to begin dropping after Tuesday night. The PacIOOS website provides information on a range of weather and ocean conditions in the Marshall Islands, as well as its “wave run-up” forecast: https://www.pacioos.hawaii.edu/shoreline/runup-majuro/