Inflation of Mauna Loa says only a matter of time

[TomK]

MarkD - with respect, no you can't say things are a big worry just because they seem overdue from using simple statistics. They do not include the physical mechanisms that cause such events.

A made up example: a volcano erupts in 1902, 1904, 1906, 1908 and 1910. It then doesn't erupt until 1990 but then erupts in 1992, 1993, 1994, and, for the sake of argument, 1999. That means it erupted 10 times in one century, so the average is one eruption every ten years. In reality, it was quiet for 80 years.

Mauna Loa is going through a similar phase that it did in the early 2000s and then it seemed an eruption was about to happen, but it didn't. That doesn't mean it won't happen soon, but it does show that you cannot simply rely on statistics to predict an eruption or anything until you have a full understanding of the mechanisms behind the eruption. For instance, Kilauea has been erupting since 1984 and Mauna Loa hasn't erupted since then. Is there a connection? Yes, many scientists think there is.

Same for tsunamis - despite the average showing we're overdue for a large tsunami hitting the islands, we've seen earthquakes just as large as those that caused previous Hawaii tsunami disasters but that hasn't happened. Yet.

Statistics are useful for many things but can also mislead you.

[PaulW]

I've been at roulette wheels where Red has been overdue for more than 10 spins; the punters nearly knock me over trying to experience the Monte Carlo fallacy for themselves.

So even if you do understand the mechanics, the concept of "overdue" is a slippery one.

[MarkD]

From Tom "...you can't say things are a big worry just because they seem overdue from using simple statistics. They do not include the physical mechanisms that cause such events."

I'd appreciate an elaboration. Maybe I used the term statistics wrong. And OK, the basis for eruptions might be completely different than that for tsunamis.

For tsunamis the situation is pretty clear. Continental drift is fixed at a few inches a year. It is largely unvarying. If the 2 plates passing by each other along the west coast do not move for 20-30 years, they will move the appropriate distance (total--or close to total) when the big earthquake comes.

Here is a quote from the article that mentioned the tsunamis: "Hawaii experienced at least one damaging tsunami every 12 years between 1837 and 1975—but none causing any significant damage in the last 35 years."

The article was written in 2009. Make that now 44 years with no big tsunami to strike Hilo. Are we not statistically overdue?

[HereOnThePrimalEdge]

Are we not statistically overdue?

If statisticians could reliably predict catastrophic events such as volcanic eruptions, more people would look to their records, tables, and graphs, rather than to the current group of prognosticators like psychics, numerologists, end-of-the-world-preachers, and the ever reliable "Predictions for 2018!!!" published in the year end edition of the National Enquirer.

Recycle Puna. Humans, although probably not you personally, have already left 400,000 pounds of trash on the moon. - YouTube's Half As Interesting

[MarkD]

Sorry I meant are we not statistically overdue for a tsunami? (based on the science of plate tectonics).

I understand the mechanism for eruptions is different (or I believe that is what I am being told).

[PaulW]

I think tsunamis are almost impossible to predict, there are too many variables, especially here in Hawaii - we're in the middle of the Ring Of Fire.
It's easy to pick out patterns in hindsight, but the future does not feel compelled to act accordingly.

[MarkP]

Tsunamis are caused by earthquakes. We have had earthquakes in our neighborhood (Pacific rim/ring of fire) lately but by chance they have not caused tsunamis. So we are not statistically overdue for the causative events for tsunamis. It has just been chance that recent earthquakes did not cause the type of displacement that results in tsunamis.

An earthquake that can justifiably be considered a destructive whopper to us occupants of high-rise buildings on land might only cause sideways displacement of the the ocean floor (no tsunami) or it might just as easily cause a vertical displacement (big tsunami).

[Durian Fiend]

quote:

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Originally posted by geochem

[quote]

There may be no time for either - a "surprise" eruption (as occurred in 1984) could easily have lava flows in the ocean (and through a few back doors) in a couple of hours time.... If it happens at night, HVO won't even know where the flows are traveling since they can't fly at night...

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Are you sure this is still a possibility? I was under the impression that the greater amount of monitoring dedicated to this volcano and the improved methods of doing so have removed this hazard.

[glinda]

I was under the impression that the greater amount of monitoring dedicated to this volcano and the improved methods of doing so have removed this hazard.

Consider a scenario in which, as is often the case, Mauna Loa in the last few hours before the onset of eruptive activity has numerous shallow earthquakes in and around the summit caldera which has HVO on a heightened state of alert. At this point would it be expected that they would make a recommendation to Hawaii County Civil Defense (CD) to evacuate anyone? Keep in mind HOVE is more than 20 miles from Mauna Loa's summit.

When the eruption begins, again, as is so often the case, at the summit and can go either way, East or to the Southwest, or as there is evidence of many independent vents on other flanks of the volcano at this point it would be anyone's guess as to where the vents might propagate. Or the volcano might just continue to erupt at the summit. All of these scenarios are possible. So, do they issue evacuation notices at that point? And, if so, how? By texting all the folks on island? Does this make for a safe and orderly evacuation without casualties?

Here is a short description of the 1950 Eruption:

"In March 1950, Mauna Loa inflation was so significant that tilt was recorded at the summit of Kilauea. Two months later, continuing deformation was accompanied by a sharp increase in small earthquakes, signaling the increased probability of an eruption.

On May 29, an island-shaking magnitude-6.4 earthquake occurred beneath Mauna Loa's west flank. Sixty-four hours later, at 9:04 p.m., HST, on June 1, the eruption began, with fissures opening at the summit and uppermost Southwest Rift Zone of the volcano.

The fissure eruptions quickly spread down rift—from 3,845 to 3,350 m (12,600 to 11,000 ft) elevation—sending floods of lava to the west and southeast. Volcanic gas emissions fed a mushroom-shaped cloud up to 3,050 m (10,000 ft) high above the volcano’s summit.

By 10:30 p.m., the Southwest Rift Zone had “unzipped” down to an elevation of 2380 m (7800 ft), unleashing an 18-km- (11-mi-) long trail of spectacular lava fountains that fed several large-volume, fast-moving lava flows. These flows reached the south Kona coast in about 3 hours, endangering lives, destroying property, and severing the main highway and telephone lines along the way.

The eruption lasted 23 days and produced 376 million cubic meters (491 million cubic yards) of lava, with over 90 percent of that volume issued during the first six days of the eruption. With an eruption rate 200 times greater than that of Kilauea's current eruption, the 1950 Mauna Loa eruption produced more lava in six days than Pau Oo typically erupts in over 4 years."

Given this scenario at what point does CD issue evacuation notices? And, when they do how many people will then be mobilized on the narrow roads available. Keep in mind there is only one highway out of the area and in 1950 before the first day of eruption had passed it was dissected in 4 places along more than 20 miles.

Conversely, what if CD takes a much more long term conservative approach and when HVO says an eruption is "possibly" imminent they issue a voluntary evacuation notice to a wide swath of the West slope of Mauna Loa, how many folks would actually evacuate?

But yes, HVO has plastered Mauna Loa with instruments. Any activity, ground deformation, seismic, an increase in gas emissions all will be documented in incredible detail but still I do not think this equates to civil defense kind of policies designed to keep us all safe. In fact, I think the entire western flank of Mauna Loa from South of Captain Cook to HOVE is a death trap, and nothing, other than a massive increase in population has happened there since 1950.

If this all takes place at night, which is pretty much a 50/50 bet, well god forbid.

[kalakoa]

Keep in mind there is only one highway out of the area

HAHAHAHA