Long-Period Earthquake Swarm

[Obie]

Saw this and had to share !

STORY SUMMARY

HAWAII VOLCANOES NATIONAL PARK - On Tuesday, scientists measured the level of the K#299;lauea summit lava lake at 74 ft. below the floor, but it dropped on Wednesday.

http://www.bigislandvideonews.com/2018/0...r-volcano/

Toward the end of the article they say "don't worry" and then post this explanation !

"Long-period (LP) or low-frequency (LF) earthquakes are caused by cracks resonating as magma and gases move toward the surface. They are often seen prior to volcanic eruptions, but their occurrence is also part of the normal background seismicity at some volcanoes and their occurrence does not necessarily indicate that an eruption is imminent. LF events can also be produced by non-magmatic processes, most notably glacier movement.'

i didn't know there was a glacier under Kilauea !!

[TomK]

They are just saying that low-frequency earthquakes can also be caused by glaciers, not that there are glaciers under Kilauea. If you read the original HVO article you'll see it's about volcanoes and seismicity in general. For example, I suspect earthquakes caused by glaciers is something you have to take into account when studying volcanoes in Iceland.

[punaticbychoice]

TomK @ 21:14:43 03/07/2018-
Alaska too methinks.

[eigoya]

So if glacial movement is NOT the cause of Kiluaeaus seismicity, can we conclude the surge is "prior to volcanic eruption"? What is "soon" in geologic time?

[Obie]

I just posted this because I think the reporter did a poor job by adding in the part about glaciers.

I was laughing after I read it.

[TomK]

I agree, Obie, Big Island Video News could have simply left that bit out of their quote. Glaciation is certainly not what the HVO implied was the cause of earthquake swarms at Kilauea. Unfortunately, science is often misrepresented in the press and since most of the public get their information via the press, it can have unfortunate effects.