Tsunami Fears ‘Unfounded’

With the continuing volcano and earthquake activity on Hawaii Island, many Molokai residents have their bags packed, ready to run for higher ground in case a tsunami is triggered. But Cindi Preller, duty scientist and geologist at the Pacific Tsunami Warning Center, said that scenario is highly unlikely.

“The tsunami fears being propagated are unfounded,” she said. “The likelihood of a collapse from Kilauea is super low. The scary scenario that people are referring to is Mauna Loa [which is not currently erupting]. Kilauea has a buttress of sediment on the ocean floor… even if it does slide, it wouldn’t slide very far.”

The wall of sediment, or fine soil, would help slow any movement to a crawl. Kilauea tends to “slump,” which is a slower type of movement not associated with tsunamis, according to the U.S. Geological Survey (USGS).

In comparison, the Mauna Loa volcano typically produces faster lava movement but GPS monitoring stations on Mauna Loa indicate no recent movement or activity and are “rock solid,” Preller said. Mauna Loa’s last eruption was in 1984.

Kilauea, located on the south east side of Hawaii Island, has been active since early this month, with more than 2,000 residents leaving evacuation areas. Twenty fissures — or linear vents in the ground — have opened as of Sunday. Despite the beauty and destruction of the flowing lava and spewing fissures, the widespread fear of a collapse of the side of Kilauea causing a landslide and triggering a massive tsunami is false, according to experts.

“There is no geologic evidence for past catastrophic collapses of Kilauea Volcano that would lead to a major Pacific tsunami, and such an event is extremely unlikely in the future based on monitoring of surface deformation,” states the Hawaii Volcanoes Observatory USGS website. “Geologic history combined with models of south flank motion suggest that the likelihood of a catastrophic failure event is incredibly remote.”

Regardless of whether the danger is real or perceived, many Molokai schools sent letters home to parents earlier this month, informing them about evacuation plans and emergency contingencies as a result of the volcano activity. Some families in coastal tsunami zones packed bags and even their vehicles for a quick reaction in case of emergency. However, Molokai residents can rest easy, said experts.

Though a tsunami resulting from the volcano is highly unlikely, what potentially might be more concerning for Molokai is vog, said Charlie Woodrum, a meteorologist at the Pacific Tsunami Warning Center.

“We are going to remain in a tradewind pattern over the next [week] so that’s good news for Molokai,” said Woodrum last Friday. That means any vog would remain south of Hawaii Island. “We’ll have to keep an eye on that [wind direction]. If they go easterly or southeasterly, that becomes a concern for Molokai.”

He pointed out that though concern for hazardous vog on Molokai is low, it’s worth monitoring because of how fast the volcano is evolving.

The state Dept. of Health is keeping a close eye on the concentration of volcanic emissions and gases in the air that could pose a health hazard. With more new fissures opening, the concentration could increase, said Woodrum.

According to the Dept. of Health, individuals with pre-existing respiratory conditions are the primary group at risk of experiencing health effects from vog exposures. Healthy people may also experience symptoms, however, like eye, nose and throat irritation, and chest tightness or shortness of breath. The Department recommends staying indoors, using an indoor air cleaner device if you’re in an exposure area, limiting strenuous physical activity and keeping medication handy if you have asthma or another respiratory condition.

Woodrum said seeing the effects of an volcanic ash plume is also low risk for Molokai.

“Another unlikely threat would be ash dispersed from the volcano,” he said. ” Normally, upper level winds would push it to the east of Hawaii Island.”

images of ash plumes from Kilauea’s Halema`uma`u Crater have become a common sight this month and triggered local ash fall advisories. But Woodrum explained that even if an eruption pushed ash 40,000 feet in the air, winds at 20,000 feet would be unlikely to bring it towards Molokai because of the dominant wind patterns.

Dozens of small earthquakes have also been rocking Hawaii Island, and on May 4, a 6.9 magnitude earthquake there was felt by some residents on Molokai. But Preller said even larger quakes wouldn’t pose a risk.

“Even if we had another [larger magnitude earthquake] I don’t consider that dangerous for Molokai,” said Preller. “I don’t see a scenario that would put Molokai in danger.”

For more information on volcano activity, visit volcanoes.usgs.gov. For air quality info and vog tips from the Dept. of Health, visit health.hawaii.gov and click on the Hawaii Vog Information Dashboard.