Saturday, February 14, 2015

[Geology2] Earthquake Week: Possibility of Mauna Loa erupting?




By Cam Tran

Earthquake Week: Possibility of Mauna Loa erupting?

Published  8:27 PM HST Feb 13, 2015


VOLCANO, Hawaii —This sleeping giant which makes up half the Big Island might be waking up.

"Looks like Mauna Loa is showing some signs of activity," said Frank Trusdell, volcanologist with the Hawaiian Volcano Observatory.

Trusdell says he's noticing more earthquakes and changes to the surface called deformation. These are key items scientists monitor for an eruption.

"We are getting small numbers of earthquakes both on the west flank and the summit. And deformation wise, we are getting extension across the flank and across the summit," said Trusdell.

But, he says the size and amount of earthquakes is still far from the activity he saw before the 1984 Mauna Loa eruption.

"Now we might be getting somewhere between zero and eight or t10 a day. When we were expecting in '75 and '84, we were having five a day, then 20 a day then 50 to hundreds a day and stay fairly consistent over that time," said Trusdell. "Those seismicity is fairly sporadic and not persistent or consistent enough for us to forecast the next eruption of Mauna Loa."

Though scientists say no eruption is imminent, if Mauna Loa were to erupt, the hazard could be immediate.

"South Kona is very vulnerable to fast moving lava flow some people only have a matter of a few hours to respond," said Trusdell.

In fact, the three 1950 flows on the southwest flank of Mauna Loa reached the ocean in less than a day. If the flow were on the Hilo side, such as the 1984 eruption, the flow rate would be slower. The amount of lava output from Mauna Loa trumps what we're currently seeing at Kilauea.

"Kilauea is putting out in the neighborhood of 100,000 cubic meters a day in this current lava flow," said Trusdell. "What Mauna Loa put out in 1984 was 1 million cubic meters per hour."

There's also a big difference in speed. Kilauea, during the June 27th flow, covered 600 yards a day at its peak speed. Mauna Loa can cover roughly six miles a day.

A flow that fast could quickly cut off highways and major roadways. It would also mean thousands more would be at risk. The southwest flank of Mauna Loa has seen a boost in development since the last eruption with many building right on the old lava flows.

In Kona Paradise in South Kona, there's new half million to million dollar homes line the steep mountain side. Along with the ocean views, residents here can also see charred land from old lava flows.
In fact, one homeowner built right on top of it.

According to the last us census report, the South Kona population grew from 8,500 to roughly 10,000 in 10 years. The Ka'u district has grown by 2,600 people with the boom mostly in Ocean View where the population doubled in just the last 10 years.

Driving along Hawaiian Ocean View Estates, you can see new houses pop up along the mountain side with more on the way. Joe Tuttle lives right on an old flow and even learning about the renewed activity at Mauna Loa. He's not worried.

"I like the lava and how it is out here it is nice peaceful and quiet," said Tuttle. "I try not to think about it. I mean, if it's gonna happen, it's gonna happen. I just roll with everything. I'd actually like to see it when it happens."


When Mauna Loa does erupt, it will allow volcanologists to test a new theory about the correlation of Mauna Loa and Kilauea.

"When one volcano is very high or frequently erupting, the other one is very quiet and vice-versa. When Mauna Loa is erupting, Kileuea is quiet," said Trusdell. "Going back and looking at the long-term geological record it seems that is true."

Right now, Kilauea is stealing the show, but perhaps not for long.

"If you look at the overall robustness of Kileuea's eruption, especially in the last year or so, it's looking like it's starting to dwindle and Mauna Loa showing signs of awakening," said Trusdell. "Time will tell whether or not my hypothesis is valid or not."

In the meantime, Trusdell as well as Hawaii County Civil Defense says Big Island residents should never forget about this giant.

"What we're seeing now is, 'Hey! I'm still active too.' Even though Kilauea is over there, I'm still an active volcano don't forget about me," said Trusdell.

Video available at source

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Posted by: Lin Kerns <linkerns@gmail.com>



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