ELLSWORTH — As part of an initiative to improve Maine’s response capabilities to natural disasters, emergency management agencies in the state are reviewing what should be done in the event that a tsunami bears down upon the state’s rocky shore.

For some time tsunamis had been assumed to be solely a phenomenon on the West Coast, where active fault lines between tectonic plates in the planet’s crust cause relatively frequent earthquakes, according to officials. When significant earthquakes happen under the ocean floor, they can cause massive tsunamis, such as one that struck several Indian Ocean countries in December 2005 or another that slammed into Japan in March 2011, crippling the Fukushima nuclear power plant in Okuma.

According to federal and state officials, recent research about tsunamis in Maine revealed that “quite a few” had disturbed Maine’s coastline or offshore waters since the late 1800s. One of them happened as recently as 2008 in Boothbay Harbor, when tidal surge rapidly and repeatedly drained and refilled the local harbor.

“To [researchers’] surprise, not all were caused by seismic events such as earthquakes or underwater landslides,” Dwane Hubert of Maine Emergency Management wrote in an article recently published in Coastal Services magazine, which is published by the federal National Oceanic and Atmospheric Administration.

The Boothbay Harbor event, Hubert wrote, “is thought to have been a meteorological tsunami, or meteo-tsunami, [which is] an event generated by squalls or other dramatic air pressure changes.”

One such tsunami occurred off the New Jersey coast last June and was detected by approximately 30 tidal gauges stationed throughout the northwest Atlantic Ocean, Hubert wrote in the article.

In 2009 and 2010, state and federal officials teamed up to research the potential for tsunamis in Maine and examined different scenarios for how tsunamis might manifest. Some scenarios indicated that tsunamis spawned near the Maine coast could hit shore within a matter of minutes but other scenarios suggested there likely would be several hours of advance warning.

“Under many scenarios, emergency managers would have five to six hours to clear Maine’s coastal populations from the danger zone,” Kitty Fahey of NOAA’s Coastal Services Center wrote in a prepared statement released last week. “With the aid of geological analysis, animated visuals and customized communication strategies, [MEMA] and coastal county emergency managers have sized up the nature of the threat and established a plan to mobilize for action as efficiently as possible.”

Mike Hinerman, director of the Washington County Emergency Management Agency, said in the Coastal Services article that county officials would use social media to help alert residents about an approaching disaster.

“Using police sirens and bullhorns or going door to door will not work in our county, which is extremely rural,” the article quoted Hinerman as saying. “We do have a very close-knit community and word spreads quickly. Once a tsunami warning is posted on Twitter and Facebook, it will spread like wildfire, so that is part of our communication plan.”

The threat of earthquakes and tsunamis has raised some concerns about the vulnerability of nuclear power plants in the U.S. and Canada. A 2011 Canadian Press article quoted an official at the nuclear power plant at Point Lepreau in New Brunswick as saying that the threat of tsunamis poses an “extremely low risk” to the plant, but also quoted one critic who said that the Fukushima plant was considered safe from natural disasters by nuclear power regulators until the March 2011 tsunami struck.

More information about the threat of tsunamis on the East Coast can be found on the NOAA website at www.tsunami.noaa.gov/.