TONGA ERUPTION RATTLES OREGON

On Jan. 15 at around 5 p.m. local time, the Hunga Tonga-Hunga Ha’apai volcano erupted in the South Pacific Ocean – reported to be the biggest volcanic event in the world over the past three decades.

This eruption produced a 260-km wide ash cloud and about 400,000 lightning strikes over the course of three hours. It also caused a tsunami with waves that were over a meter high and set off tsunami warnings on the U.S. West Coast.

It was initially thought that Oregon’s coast could get waves reaching 3 or 4 feet high; however, the warning was lifted by Sunday morning. The highest waves recorded on the West Coast were in Port San Luis, California, reaching 4.3 feet. Oregonians were still warned to stay away from the beaches because of the strong and unpredictable currents caused by the tsunami that could easily pull people far out into the sea.

One big question being asked about the massive eruption is if it will impact the world’s climate. In a New York Times article titled “Heard, Felt but Barely Seen: How a Volcano Severed Tonga From the World,” Sydney, Australia bureau chief Damien Cave wrote, “Although it appeared to be the largest eruption in the world in three decades, the explosion of the Hunga volcano on Saturday will very likely not have a temporary cooling effect on the global climate, as some past enormous eruptions have.”

Unfortunately, the eruption did cause a significant amount of damage to the nearby area, including an ash deposit that will most likely cause environmental damage there for the next few years.

As of now, only three deaths have been confirmed from the eruption, but there is currently a “communication blackout” due to damage to an undersea cable, so the amount of damage that has been done is still unclear. Yet, in another New York Times article titled “Three Tiny Islands Have Borne the Brunt of Tonga’s Tsunami,” reporter Natasha Frost wrote, “Nomuka, Mango and Fonoifua [three of Tonga’s islands] were buffeted by waves almost 50 feet high, compared with waves of only 4 feet on Tongatapu. On Mango, brown and gray ash deposits now cover the entire island, and the settlement there, which once included a school and a simple, red-roofed church, appears to have been swept away, an analysis from the United Nations showed.” There also have been major concerns about air, food, and water contamination due to the amount of ash falling.

As noted, Oregon was warned of a possible tsunami from the eruption – and it would not have been the first time the Oregon coast has experienced one.

The most recent one came on March 11, 2011. The Oregon coast suffered waves 3 to 4 feet high as a result of the 9.1-magnitude Tohoku earthquake in Japan, where waves reached about 130 feet. Four people were reportedly injured in Gold Beach and in California, one man was swept out to sea and drowned. A delayed wave later that day hit Port Orford’s marina in southern Oregon, and caused millions of dollars in damage.

The biggest reported tsunami to hit the Oregon coast (in modern times) was on March 27, 1964. A magnitude 9.2 earthquake shook Prince William Sound, Alaska, the biggest earthquake the U.S. has ever had, and this sent large waves to the West Coast – as high as 12 feet. Bridges were

torn down, houses flooded, powerlines were taken out, and four children got swept out to sea and drowned near Lincoln City while their parents were pinned down by the water.

And while this time, there wasn’t much of an impact in Oregon, this month’s tsunami warning has given us another opportunity to prepare for the huge, offshore Cascadia subduction zone earthquake that the West Coast is overdue for.

Notable Oregon Tsunamis

Since 1854, 21 tsunamis have impacted the Oregon Coast, per the Oregon state Office of Emergency Management.

· January 1700: approx. 9.0 magnitude Cascadia subduction zone earthquake off Oregon/Washington coast; tsunami devastates PNW native communities and coastline

· April 1946: 8.6 magnitude earthquake in Alaskan Aleutian Islands; surge reaches Oregon (kills more than 160 people in/near Hilo, Hawaii)

· May 1960: 9.5 magnitude earthquake in Chile, South America; surge reaches Oregon (kills 61 people in Hilo, Hawaii)

· March 1964: 9.2 magnitude earthquake in Alaska; surge hits Oregon and West Coast, four children killed on central Oregon Coast, 11 killed in Crescent City, California

· March 2011: 9.0 magnitude earthquake off Honshu Island, Japan: surge hits Oregon and West Coast, kills one person in northern California