02-12-2018, 11:41 AM
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.
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.