USGS issues first USA Volcano Threat Assessment in over a decade

18 volcanoes in the USA are classified as “very high threat”, many are in the Pacific Northwest.

The United States has 161 young, active volcanoes within its borders. Since 1980, there have been 120 eruptions and 52 episodes of notable volcanic unrest at 44 U.S. volcanoes.

The U.S. Geological Survey systematically assesses U.S. volcanoes considered to be active or potentially active, and publishes a volcanic threat assessment that ranks the volcanoes based on 24 hazard and exposure factors. Last published in 2005, this 2018 update considers (1) field and laboratory research that adds or removes volcanoes from the list of potentially active volcanoes, and (2) updates the hazard and exposure factors used to produce a relative threat ranking of volcanoes.

The 2018 update of the 2005 assessment adds or raises the threat level for 12 volcanoes and reduces or removes threat level status from 20 volcanoes. The threat ranking is not an indication of which volcano will erupt next. Rather, it is an indicator of the potential severity of impacts that could result from future eruptions at any given volcano.

The volcanic threat assessment is used by the USGS to help guide and prioritize risk mitigation efforts at U.S. volcanoes through volcano research, hazard assessment, emergency planning and preparation and monitoring efforts with federal, state and local government partners. The prioritization of risk mitigation efforts is a cornerstone in the development of the National Volcano Early Warning System.

The 2018 Update to the U.S. Geological Survey National Volcanic Threat Assessment is available online.

This revised threat assessment includes 18 very high threat, 39 high threat, 49 moderate threat, 34 low threat, and 21 very low threat volcanoes. The total of 161 volcanoes is a decrease of 8 from the total reported by Ewert and others (2005)

Map showing locations of all U.S. volcanoes with threat category designated by color. NVEWS, National
Volcano Early Warning System.


Here is a table of the top threats:

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John Tillman
October 24, 2018 1:51 pm

The list of 18 very high threat volcanoes determined by Ewert and others (2005) remains the same; 11 of the 18 volcanoes are located in Washington, Oregon, or California, where explosive and often snow- and ice-covered edifices can project hazards long distances to densely populated and highly
developed areas. Five of the 18 very high threat volcanoes are in Alaska near important population centers, economic infrastructure, or below busy air traffic corridors. The remaining two very high threat volcanoes are on the Island of Hawaiʻi, where densely populated and highly developed areas now exist on the flanks of highly active volcanoes. The high- and moderate-threat categories are dominated by Alaskan volcanoes.

1 Kīlauea HI 48 263 19.425 -155.292
2 Mount St. Helens WA 59 235 46.2 -122.18
3 Mount Rainier WA 37 203 46.87 -121.758
4 Redoubt Volcano AK 48 201 60.485 -152.742
5 Mount Shasta CA 39 178 41.42 -122.2
6 Mount Hood OR 30 178 45.374 -121.694
7 Three Sisters OR 30 165 44.133 -121.767
8 Akutan Island AK 47 161 54.134 -165.986
9 Makushin Volcano AK 47 161 53.891 -166.923
10 Mount Spurr AK 48 160 61.299 -152.251
11 Lassen volcanic center CA 32 153 40.492 -121.508
12 Augustine Volcano AK 48 151 59.363 -153.43
13 Newberry Volcano OR 30 146 43.722 -121.229
14 Mount Baker WA 15 139 48.777 -121.813
15 Glacier Peak WA 37 135 48.112 -121.113
16 Mauna Loa HI 4 131 19.475 -155.608
17 Crater Lake OR 37 129 42.93 -122.12
18 Long Valley Caldera CA 29 129 37.7 -118.87

Cascades (WA, OR, CA): 10
Alaska: 5
Hawaii: 2
Non-Cascade CA: 1

Remarkable that Yellowstone isn’t on the VHT list. Maybe because its next eruption is not expected any time soon, but criteria include proximity to population, as well. Yellowstone is remote, but its ejecta would cover a vast area.

Reply to  John Tillman
October 24, 2018 3:35 pm

Notice that they didn’t even need to include any part of the US East of the Mississippi — no volcanoes over here where I sit.

Alaska alone accounts for more than half of the volcanoes (86 out of 161). Almost all in the Pacific and on the Pacific Rim.

John Tillman
Reply to  Kip Hansen
October 24, 2018 4:16 pm

Yup. Typical of Earth in general. Onshore volcanoes are concentrated near subduction and rift zones. Much like earthquakes, although there are some big seismic areas in the middle of apparently stable regions, such as New Madrid, MO.

Pop Piasa
Reply to  John Tillman
October 24, 2018 5:49 pm

Yeah, rub it in for me, here at the confluence of the Mississippi and Illinois rivers. The New Madrid zone has been theorized to be on a 200 year cycle. Hopefully the last release was abnormally high. I do see billboards while driving through the region which give earthquake instructions and have noticed that Walmart has held drills in these areas in conjunction with local/regional first responders.

Alan Tomalty
Reply to  Pop Piasa
October 24, 2018 7:47 pm

At least they can’t blame CO2 on volcanos.

Reply to  Pop Piasa
October 25, 2018 12:54 am

Anything can be blamed on Co2 !

Tom Abbott
Reply to  Pop Piasa
October 25, 2018 7:21 am

I saw a tv show yesterday on the Science Chanel that claimed that the Mississippi River was a failed rift zone. The continent tried to split apart along the path of the river and then for some unknown reason, the pulling apart stopped and the rift progressed no farther.

Reply to  Pop Piasa
October 25, 2018 9:24 am

“HOOEY”, ….. t’was no “rifting” involved in the creation of the Mississippi River channel.

The Mississippi River is the remnant of the Western Interior Seaway, also called the North American Inland Sea, to wit:

But on the contrary, the Grand Canyon of the Colorado River is the result of a rifting “rift zone”.

Tom Abbott
Reply to  John Tillman
October 26, 2018 4:35 am

““HOOEY”, ….. t’was no “rifting” involved in the creation of the Mississippi River channel.”

Well, someone should tell the producers of the science program NOVA. They had a program on volcanoes the other day, and at one point it was stated flatly that the Mississippi River started out as a rift zone. They were comparing it to the East African rift zone and speculating whether the East African rift zone would stop spreading like the Mississippi rift did.

I admit that’s the first time I have ever heard that said about the Mississippi river, which is the reason I posted it, to find out what others thought about it.

Reply to  Tom Abbott
October 27, 2018 4:25 am

Well, someone should tell the producers of the science program NOVA.

T’wouldn’t do any good, NOVA just produces sciency programs based on what they think their viewers want to see/hear. They don’t do the science, they choose the science.

To wit:

The Western Interior Seaway was a large inland sea that existed during the mid- to late Cretaceous period as well as the very early Paleogene, splitting the continent of North America into two landmasses, Laramidia to the west and Appalachia to the east. The ancient sea stretched from the Gulf of Mexico and through the middle of the modern-day countries of the United States and Canada, meeting with the Arctic Ocean to the north. At its largest, it was 2,500 feet (760 m) deep, 600 miles (970 km) wide and over 2,000 miles (3,200 km) long.

Subduction and uplift, but not rifting. The area was already, per se rifted, at 2,500+ feet deep prior to 66+ mya.

Pamele Matlack-Klein
Reply to  Samuel C Cogar
October 27, 2018 6:27 am

There is a SF story called The Great Nebraska Sea, by Allan Danzig, that I read a long time ago. Now it can be found online. It was a great bit of geological science fiction and fascinated me at the first reading. As the story goes, the Nebraska Sea returns when the middle of the country subsides and the Mississippi River flows backwards to fill the depression from the Gulf. Millions are killed, more millions are displaced and chaos rules for a while. But then the waters clear and the fishing is fantastic, the climate ameliorates thanks to the new sea and things are pretty good again in the middle.

Reply to  Tom Abbott
October 27, 2018 6:58 am

In respectful regard to Samuel’s comment, the Cretaceous Western Interior Seaway was further to the west than the Mississippi Embayment.

Subsurface studies continue to add to the volume of information and interpretations do change over time.

Unless it has changed, one interpretation of how the Mid-Continent failed-rift influenced the Mississippi Valley was that the rift progressed far enough to produce some oceanic crust (much denser than the adjacent continental crust) and within the New Madrid Fault Zone, that denser oceanic crust is trying to sink back into the mantle. (As the area is protected from collisions along the continental margins, it hasn’t been appreciably “mashed” or otherwise laterally-distorted since the failed rifting.)

That “crustal sagging” has affected the Mississippi Embayment since at least the Cretaceous, perhaps during the preceding Jurassic, too. IOW, the Embayment has been there much longer than the river.

As for the Grand Canyon being rift-related, where did that notion come from?

(I received my M.S. in Geology from UT El Paso in 1990 and have been visiting/studying about/working in the western U.S. since 1973.)

Reply to  Tom Abbott
October 28, 2018 8:24 am

ontherocks – October 27, 2018 at 6:58 am

In respectful regard to Samuel’s comment, the Cretaceous Western Interior Seaway was further to the west than the Mississippi Embayment.

IOW, the Embayment has been there much longer than the river.

Ontherocks, exactly correct you are, …… and of course the Mississippi Embayment had been there a WEE BIT longer than the Mississippi River. And “YES”, right again, the Western Interior Seaway was further to the west than the Mississippi Embayment.

“DUH”, when the Western Interior Seaway existed ….. there was no frigging reason in the Paleozoic world for the Mississippi River to even exist, ….. let alone a Mississippi Embayment area. Any water (rain, snow melt or artesian) in the later defined/designated Mississippi Embayment locale would have drained/flowed into the Western Interior Seaway.

And “DUH, DUH”, the Mississippi Embayment area and the Mississippi River didn’t, couldn’t have, come into existence until AFTER the Western Interior Seaway began its lopsided “uplifting” with its western edge rising the most. Even to this day, it is a fairly steady “uphill” climb from Saint Louis, MO, to the Colorado Plateau in Colorado and/or New Mexico. And it was the lopsided “uplifting” that created the Mississippi watershed.

ontherocks – October 27, 2018 at 6:58 am

As for the Grand Canyon being rift-related, where did that notion come from?

Well, it came from me and several other “original thinkers” via their use of their common sense, logical reasoning and intelligent deduction.

There is absolutely no way in hell that the erosive force of the Colorado River could be responsible for “carving out” the Grand Canyon. And likewise, there is absolutely no way in hell that the erosive force of a HORRENDOUS “flash flood” could be responsible for “carving out” the Grand Canyon.

The topography of the GC, with it “mile high” straight faced cliffs or rock walls, ….. its width in some places of up to 10 miles wide from brim to brim …….. and its numerous deep, dead ended, side channels …… is pretty much scientific confirmation that “rifting” is the only possible cause of its creation.

Like this view of the Grand Canyon apply demonstrates the result of said “rifting”. Or more like “ripping”, ….. jaggedly ripping the Colorado Plateau apart during the “uplifting”.

Cheers, Sam C, …… AB, Biological and Physical Science, ….. GSC 63’, ….. original thinker, inventor, logician and computer designing dinosaur. 😊 😊

And ps, …. iffen you were awarded an M.S. in Geology from UT El Paso in 1990 ……. then you HAD TO believe what they were teaching you or they would have “failed” you and thus no MS degree.

Reply to  Kip Hansen
October 24, 2018 5:07 pm

Jackson Volcano, Doorpoint Volcano, A Jurassic era volcanic field south of Mobile Alabama. Several plutonic emplacements in and around the Reel-foot Rift, Yep, nothing east of the Mississippi to worry about.

Reply to  Tweak
October 24, 2018 5:12 pm

We’re probably OK on Mesozoic volcanoes.

Don K
Reply to  Tweak
October 24, 2018 6:10 pm

I think the last really serious, rip up the countryside, vulcanism in Eastern North America was the Great Meteor Hotspot. It left a trail of volcanoes from Montreal across New England. It moved off into the Atlantic in the Mid to Upper Cretaceous. It has since passed under the Mid Atlantic Ridge — leaving a trail of seamounts behind it and is currently under the Great Meteor Seamounts off the coast of Africa.

Reply to  Don K
October 27, 2018 8:39 am

There are some Eocene extrusives and intrusives in the Virginia Valley & Ridge Province, not sure what the most up-to-date interpretation is. If memory serves me correctly, they were only discovered within the last 15 years or so. I think they are older than the Chesapeake Bolide impact.

Hidden beneath the soil and vegetation of the remainder of the Appalachians, I wonder if there are more igneous surprises yet to be found? In a few places in the north Georgia mountains, tiny diamonds have been found, but thus far, no apparent source rock(s). I wonder if these diamonds suggest post-orogenic igneous activity? (The Prairie Lake diatreme – which hosts the Arkansas diamonds – is of Cretaceous age.)

Reply to  John Tillman
October 24, 2018 5:50 pm

Yellowstone Caldera is number 21 on the list

Reply to  John Tillman
October 26, 2018 8:33 am

Small point but Long Valley Caldera is in the Sierra not the Cascades.

michael hart
October 24, 2018 2:00 pm

Honestly, you wouldn’t believe what the UK wouldn’t give for an active volcano for people to visit.
In The North, Scotland, or Wales, of course.

John Tillman
Reply to  michael hart
October 24, 2018 2:07 pm

Most people in the US and Canada have to travel far to visit one, most of the time. Our currently erupting volcanoes are in Hawaii and Alaska. The last eruption in CONUS was Mt. St. Helens in 2008, IIRC, which I might not.

Kilauea has been erupting continuously since 1983.

The UK is closer to Mt. Etna, Sicily than are most Americans to AK and HI, or even Oregon and Washington.

Reply to  John Tillman
October 24, 2018 2:19 pm

For we Canadians it’s quite convenient that they stop at the border. Tempting sometimes to put our toes over the border into the”danger zone” as we like to call the U.S. Lol!

John Tillman
Reply to  john
October 24, 2018 2:27 pm

You have your own danger zones. Canada is blessed or cursed with more than 200 potentially active volcanoes, 49 of which have erupted in the past 10,000 years. Forty-six of the eruptions were effusive and three explosive.

But granted, your stretch of the Cascades has been less active than WA, OR and northern CA.

Reply to  John Tillman
October 24, 2018 2:38 pm

Just imagine how much tax Trudeau could collect of one of those mountains if it blows its top! We’d all be rich. Of course he’d spend it right away, but not on getting re-elected. NO way! Not Justin!

John Tillman
Reply to  John Tillman
October 24, 2018 2:57 pm



Your zone of maximum danger is in Ottawa.

Reply to  John Tillman
October 24, 2018 4:25 pm

It’s not quite as detailed a list as the USGS, but here’s Canada’s volcano assessment:

“The last time a volcano erupted in Canada was 150 years ago. But it will happen again.
When the Lava Fork volcano in northwest British Columbia erupted, a 22-kilometre lava flow crossed into Alaska, damming the Blue River and creating many small lakes. Since then, Canada has witnessed minimal volcanic activity.”

michael hart
Reply to  John Tillman
October 24, 2018 2:28 pm

True, but it’s still nice to have a ‘local’ one in your country.

When I lived in Seattle the conversation (in the College Inn) would occasionally turn to the prospects of Mount Rainier turning troppo.

The best the UK can manage is a little warm water leaking out of the ground in Bath. No wonder the Romans gave up and went home.

Reply to  michael hart
October 24, 2018 2:37 pm

How many of them moved to Pompeii?

michael hart
Reply to  Susan
October 24, 2018 3:01 pm

Susan, I’m not sure I should take responsibility for where this thread is going, but at least one, apparently.

The original full length movie is probably about as far as it should have gone.

John Tillman
Reply to  michael hart
October 24, 2018 2:39 pm

The Romans in Britain in AD 79 were probably happy to be there rather than in Pompeii and Herculaneum.

The UK had some pretty impressive volcanoes in the past.

It could indeed be a bad day when Rainier next pops off. There should be some warning for people downstream and downwind to evacuate.

I was in Portland when our perfectly conical, Fuji-like neighbor across the river committed seppuku. Shortly after the eruption, I flew in a WA Army National Guard Chinook around the ash-covered scenes of devastation, to include steam falls, if fall is the right word for a water vapor outpouring.

John Tillman
Reply to  John Tillman
October 24, 2018 3:01 pm

The most recently active volcanoes in the UK were in the Paleogene Period, ie Paleocene, Eocene and Oligocene Epochs of our current Cenozoic Era:

The period formerly known as the Tertiary.

Michael S. Kelly, LS, BSA, Ret.
Reply to  John Tillman
October 24, 2018 11:09 pm

I used to travel to Seattle on business, back in the 1980s and 1990s. A couple of times, I flew in over what was left of Mt. St. Helens. It was awe-inspiring. Then, one crystal clear day, I got a good look at Mt. Rainier. It was positively terrifying. I don’t know why anyone would put down roots anywhere near that beast.

Pamele Matlack-Klein
Reply to  John Tillman
October 24, 2018 3:26 pm

Despite having lived most of my life on the right coast and now in Europe, I am familiar with all the Cascade volcanoes. I’ve tramped around on the old lava fields in the area of the Three Sisters, visited Crater Lake several times, explored Lassen Volcanic Center, and Mt. St. Helens.
Mt. Shasta, Mt. Baker, Mt. Rainier, and Mt. Hood are prominent peaks and highly visible when driving in their vicinity. I’m also familiar with the other volcano park is Oregon with a cinder cone as one of its main attractions and a vast obsidian flow within the park. Most of these spots are scenic areas and popular with tourists. But, there are also hot springs throughout the Cascades and to the east in Washington and Oregon, sure indication that something can happen at any time in that subduction zone.

John Tillman
Reply to  Pamele Matlack-Klein
October 24, 2018 4:22 pm

When I was a kid, we had a cabin on the Umatilla River near a hot spring, which was just one of many in the Blue Mountains, far from the Cascades and geologically distinct. There’s a lot cooking under the northwestern USA, from the WA Cascades to Yellowstone in the Rockies.

Yellowstone is like Hawaii, except that continental crust is traveling over the hot spot, rather than oceanic. Back in the Miocene, during the Columbia Basin flood basalt eruptions, the hot spot was in SE Oregon and SW Idaho.

Reply to  John Tillman
October 24, 2018 10:14 pm

Parts of the UK are closer to icelandic eruptions.

Reply to  michael hart
October 24, 2018 2:31 pm

Decline of the Earth’s Magnetic Field Intensity in the central USA has reached what might be considered to be an alarming rate
At the current rate the field will loose 50% of its strength in about 160 years time, equalling current strength in the central area of the South Atlantic Magnetic Anomaly.

Reply to  vukcevic
October 24, 2018 2:49 pm

The latest data I have is the decline in the earth’s magnetic field is at the rate of 10% per decade which means it would lose 50% of its strength in 50 years.

Reply to  michael hart
October 24, 2018 7:26 pm

Hekla, Iceland

Mike M.
October 24, 2018 2:06 pm

Further evidence to support the cold sun hypothesis and associated global cooling? I’ve notice what seems to be an uptick in notifications popping up from my quake watch app as well. Just curious as to what others think as I’m not well versed (yet) in that particular theory and how it could affect volcanic and earthquake activity.

Gunga Din
October 24, 2018 2:07 pm

An awful lot of red on the left coast.
Is that from heads exploding?

John Tillman
Reply to  Gunga Din
October 24, 2018 2:11 pm

That, and plate tectonics.

The two most active Pacific Ring of Fire zones in North America are Alaska and Mesoamerica, with the west coasts of Canada and the continental US less so.

Reply to  Gunga Din
October 24, 2018 2:15 pm

no….CO2 causing everything!

Curious George
Reply to  Gunga Din
October 24, 2018 2:31 pm

No, unfortunately.

Reply to  Gunga Din
October 24, 2018 3:16 pm

Gunga Din
if that were the case there would be red in DC, NY, NJ, and MA.

Gunga Din
Reply to  RAH
October 25, 2018 3:56 pm

As John Tillman pointed out, plate tectonics and not political tectonics.

October 24, 2018 2:30 pm

For we Canadians it’s quite convenient that they stop at the border. Tempting sometimes to put our toes over the border into the”danger zone” as we like to call the U.S. Lol!

Reply to  john
October 24, 2018 2:31 pm

Sorry, Not sure how I managed to double up my post. Maybe too much CO2!

October 24, 2018 2:33 pm

What with winter coming here sooner or later I am thinking of gathering up some friends and migrating southward. Be at the border in a week or two if that’s ok. Just passing through on our way to Guatemala or somewhere down there.

Reply to  john
October 24, 2018 6:03 pm

You’re a funny boy, john!
Are you really planning on visiting there? Seems like an awful lot of people are passing through on their way to the land of free things. Like… they have little to offer. Maybe just not enough free things.
Is the US really more socialistic than other Central American countries?

Reply to  KaliforniaKook
October 24, 2018 11:03 pm

Only our “free-thinking” judges. They forget somebody has to pay for their largess!

Tom Abbott
Reply to  KaliforniaKook
October 25, 2018 7:36 am

“Seems like an awful lot of people are passing through on their way to the land of free things”

No doubt those marchers have visions of welfare checks, and free medical care and housing and all sorts of things in their heads right now. Dreaming big! And no doubt many of them will get just what they are dreaming of because our immigration laws make it almost impossible to deport them back to their own country immediately if they are “other than Mexican”.

We need to get our immigration laws changed, otherwise the whole world is going to be “pooring” across our border.

M Courtney
October 24, 2018 2:50 pm

There is a theory that was popular in the ’80s that tectonic activity cycles anti-clockwise round the Pacific Ocean. Thus it is now the Eastern side of the Pacific’s turn to be hit by activity.

But I never did know how Kilauea fitted in.

John Tillman
Reply to  M Courtney
October 24, 2018 2:55 pm

It’s not part of the Ring of Fire. It’s caused by the Pacific Plate passing over the Hawaiian Hot Spot, which has been responsible for all the Hawaiian Islands and the Emperor Seamounts.

The Ring of Fire, by contrast, owes to the subduction of oceanic plates under continental plates.

M Courtney
Reply to  John Tillman
October 24, 2018 3:48 pm

But what is the Hawaiian Hotspot It doesn’t fit in.

-Is it the peak of a crack in the mantle?
-Or is it where the eddies on the mantle cause a bulge into the crust?
-Or are the eddies a circular motion in the mantle with the centre adjacent to the Hawaiian Hotspot and the edges meeting the surface at the edge of the Pacific?

It doesn’t fit in. Which is interesting.

John Tillman
Reply to  M Courtney
October 24, 2018 4:26 pm

Hot spots are often associated with tectonic boundaries, but some are just randomly located around both continental and oceanic plates.

Some scientists think that at least certain spots are caused by large ET impacts, which punch through the crust. Oceanic crust is thinner, hence more vulnerable to such penetration.

Here are the locations of several:

John Tillman
Reply to  M Courtney
October 24, 2018 4:39 pm

Here’s another Pacific hotspot, with a cartoon of the standard model of how they work. In the past 20 years, some have questioned whether they all remain stationary.

The most famous hotspot in the Indian Ocean is probably that currently under Reunion Island, east of Madagascar. The Deccan Traps are attributed to the passage of the Indian Plate over this hotspot on its high-speed (geologically speaking) trip across the IO from Antarctica to collide with the Eurasian Plate, piling up the Himalayas. The Deccan Traps flood basalt eruptions occurred around the end of the Cretaceous and beginning of the Paleogene Periods, so some have blamed volcanism for the mass extinction event then, rather than or in addition to the Yucatan bolide impact.

M Courtney
Reply to  John Tillman
October 24, 2018 11:53 pm

Interesting .

October 24, 2018 3:24 pm

People always seem to be surprised when I tell them that the Mono-Inyo Craters (#24 on the list) erupted as recently as 500 years ago. They present a current danger through the release of carbon dioxide and other volcanic gasses on and around Mammoth Mountain. In 2006 three Mammoth Mountain ski patrol members were killed by the toxic gas released by a fumarole after becoming trapped when snow they were standing on above the fumarole collapsed.

October 24, 2018 3:35 pm

For anyone else with an interest in geology and an addiction to Excel…

I converted the table to an Excel spreadsheet and built a “bubble map” plot:

October 24, 2018 5:18 pm

The USGS should have included the volcanic chain that continues into Western Canada right up to Alaska.
The table should have distinguished the difference between shield volcanoes that drool and the subduction ones that do very big bangs.
I’m in a high-rise condo as far west in Vancouver as one can get. Facing south and west the view is, at times, incredible.
To the south-west at some 80 miles is Mount Baker, which is one of those that can go bang.
On a clear day it can be readily seen.
Any troubles and let y’all know.

Reply to  Bob Hoye
October 24, 2018 5:24 pm

Oops–the martini
The view to Baker is to the South-East

John Tillman
Reply to  Bob Hoye
October 24, 2018 5:45 pm


Shortly before Mt. St. Helens blew, there were more warnings for Baker.

It’s a hyperactive volcano.

Envy your view.

Reply to  John Tillman
October 24, 2018 6:17 pm

Oh Yeah. Mt. St. Helens
I was living on Point Grey Road, right on the ocean facing north.
I had to look up the date and it was a Sunday morning, nice day and I heard a modest boom.
But enough for me to go to the window, the curtains were always open, to see if one of the ships in the harbour had a problem.
Couldn’t see anything unusual and it wasn’t until a few hours later when driving the car with the radio on that I heard the news.
If it had blown straight up I might not have heard anything, but the north-facing slope failed and a lot of the energy headed north.
When I was recently graduated I had a job checking out a gold property up the Nass River from Terrace, B. C.
Parts of the valley floor were still showing lava that had flowed some 250 years ago. Rather ugly stuff.

Crispin in Waterloo but really in Beijing
Reply to  John Tillman
October 24, 2018 8:29 pm

I was in North Vancouver City when Mt St Helen’s blew up. It shook the house slightly it was so loud. That whole area is dangerous!

John Tillman
Reply to  Crispin in Waterloo but really in Beijing
October 24, 2018 9:19 pm

Bob and Crispin,

The Mt. St. Helens eruption was a prime example of what was known in the US (so-called) Civil War “acoustic shadow”.

We didn’t hear the eruption in Portland, close to it, but others closer and farther away did. It depended on the bounce off layers of the atmosphere. Watching from NW PDX, I could estimate the ash cloud height with hand over hand measurements, which proved ball park accurate.

Because the sound wave missed us, I wouldn’t even have known the volcano went off had I not been walking the child of the couple with whom I then roomed in NW PDX that morning.

John Tillman
Reply to  John Tillman
October 24, 2018 9:21 pm

PS: May 18, 1980 was a Sunday. Few were out and about at 8:32 AM.

Roger Knights
Reply to  John Tillman
October 25, 2018 5:55 am

My Seattle house got a “good” bounce. I thought a 747 had passed 50 feet above it. I went out to see where it had gone and noticed neighbors in two houses out on their porches like me. (We’d been reading or viewing warnings about the impending eruptions for months, but I don’t think any of us put two and two together in the immediate atermath.)

October 24, 2018 6:01 pm

There is a definite link between a weakening geo magnetic field and the climate/volcanic activity if the geo magnetic field is weakening in sync with a weakening solar magnetic field .

Why? Because a weakening geo magnetic will compound given solar effects. When the solar magnetic field weakens one effect is an increase in galactic cosmic rays entering our atmosphere and some reaching the surface of the earth. The weakening geo magnetic field will compound this. This increase in galactic cosmic rays will result in an increase in global cloud coverage and an increase in major explosive volcanic activity and geological activity in general which will result in a cooling climate.

Evidence of this is already taken place with earth quake activity magnitude 4.0 or higher on the rise up over 20% over the last few months while global temperatures have been trending lower post year 2016.

October 24, 2018 6:08 pm

What the f&ck these overpaid a$$holes been doing for 10 year! Are they union f&cks?!?!? Prosecute them for stealing our money!!!!!!!!

October 24, 2018 7:49 pm

I see the researchers minimized Sunset Crater’s danger into a non-threat.
One would think that a young volcano would merit some serious study.

Then again, one would think that large cities in the path of major tsunami, volcanic lahars and pyroclastic flows would get moved to safer areas.

Better to tell people to walk, not run, to a local high spot.

“San Francisco Volcanic Field (located in Arizona)
Sunset Crater

Sunset Crater, located about 25 km (15 mi) northeast of Flagstaff, Arizona, is one of the youngest scoria cones in the contiguous United States and is the youngest of about 600 such cones in the San Francisco Volcanic Field.

Sunset Crater erupted about 1085 A.D.
The cone is named for the topmost cap of oxidized, red spatter, which makes it appear bathed in the light of the sunset. In the 1920’s, H.S. Colton saved the cone from severe damage by averting the attempt of a Hollywood movie company to blow it up in order to simulate an eruption. This led to the establishment of the Sunset Crater Volcano National Monument.

The eruption of Sunset Crater began as an approximately 11-km-long fissure of lava fountaining activity, called a “curtain of fire.”
The Sunset Crater scoria cone became the focus of Strombolian- style fountaining activity and sustained violent-Strombolian eruption columns, which grew the cone and deposited widespread tephra fall.
At the same time, lava flows issued from the cone vent and reached up to 11 km (nearly 7 mi) from the source.
In the end, the eruption produced an approximately 300-m- (1000-ft-) high cinder cone, a widespread tephra fall deposit (2300 km2, 890 mi2) with thicknesses of up to 12 m (40 ft), and three lava flows that cover about 8 km2 (3 mi2).

Prehistoric communities living in the area at the time of the eruption were certainly impacted. Archeological records indicate that the area was densely populated with independent groups of humans with permanent habitation sites and agricultural fields, which were abandoned as a result of the eruption. The population moved to a new environment at a lower elevation just a few tens of kilometers away, which required them to enact technological changes that allowed the population to thrive. There is evidence of humans interacting with the volcano as it erupted – there are pieces of Sunset Crater scoria with impressions of corn kernels and husks. These “corn rocks” are believed to have been made when people placed ears of corn near hornitos, spattering vents that form above lava flows or tubes. As spatter erupted from these vents it covered the corn then cooled to create a corn mold. Some of these rocks were found in the walls of habitation structures greater than 4 km away from the closest Sunset lava flows.”

Reply to  ATheoK
October 27, 2018 10:53 am

While doing some reading on volcanoes a few days ago, I ran across the interesting opinion that individual young, small volcanoes and their associated fissure zones don’t seem to show a propensity to easily “come back to life”, once “extinct”.

While I don’t recall the exact reasoning, it would seem that with the eruptive cessation of a small volcano, the smaller associated conduit(s) seal themselves more easily than the large conduits of large volcanoes. (This may not apply to Hawaiian volcanoes.)

Some examples, aside from Sunset Crater, might be the Mono-Inyo Craters (CA) and Little Black Peak (Carrizozo, NM, erupted ca. 5,000 years ago). That is not to say that the particular area associated with a particular volcano, i.e., the “volcanic field” is not susceptible, it is best to keep an open mind. Different Geologists will have different views on the possibility of future eruptions in established areas. Aside from Little Black Peak, there are numerous potentially active areas associated with the Rio Grande Rift, the San Francisco Volcanic Field (Flagstaff, AZ), and the Clayton-Raton Volcanic Field (NE New Mexico).

(Those NM and AZ volcanoes are the ones most familiar to me.)

October 24, 2018 8:55 pm

October 25, 2018 8:05 am

Interesting how they ranked Mt. Hood. Local geologist consider it dormant and not an imminent threat followed up by “if” it did wake up it has the potential to wipe out Portland. Looks like this study mostly looked at the potential threat if it does wake up more than if it’s likely to become active any time soon.

October 26, 2018 10:10 pm

How to weaponize a volcano, according to a Russian military expert, reported by RT.

Russia is able to produce nuclear weapons with a yield of more than 100 megatons.
“If “areas with critically dangerous geophysical conditions in the US (like the Yellowstone Supervolcano or the San Andreas Fault)” are targeted by those warheads, “such an attack guarantees the destruction of the US as a state and the entire transnational elite,” he said.”

October 27, 2018 7:21 am

You can not weaponize a volcano.

Reply to  Salvatore Del Prete
October 27, 2018 10:29 am

Would be one helluva concealed carry piece!

Reply to  Salvatore Del Prete
October 28, 2018 9:54 am

Various scenarios: The Russian guy’s comment was sarcastic. The Russian guy is a left-over from the Cold War. The Russian guy accidentally let slip the plot of a future James Bond movie. The Russian guy is just bragging, to encourage disarmament. The Russian guy is planting a seed of doubt and worry and the next step will be to monetize the volcano. He will claim the volcano has already been hacked and everybody had better send a gazillion dollars to his BitCoin account, or else.

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