'ANCIENT-LOOKING' BOMBS IN HAWAII VOLCANO REDISCOVERED 85 YEARS AFTER THEY WERE DROPPED TO SAVE TOWN FROM LAVA
BY HANNAH OSBORNE NEWSWEEK 3/9/2020
Bombs dropped into a volcano by the U.S. Army 85 years ago in a bid to divert lava from a nearby town have been rediscovered.
The bombs, which were dropped as part of a cluster in 1935, were reported by local media at the end of February, and Hawaii Volcano Observatory (HVO) has now explained the presence of these "ancient-looking bombs" for its weekly Volcano Watch article
Bombs dropped into a volcano by the U.S. Army 85 years ago in a bid to divert lava from a nearby town have been rediscovered.
The bombs, which were dropped as part of a cluster in 1935, were reported by local media at the end of February, and Hawaii Volcano Observatory (HVO) has now explained the presence of these "ancient-looking bombs" for its weekly Volcano Watch article
Last month, Hawaii News reported that Kawika Singson had found the unexploded bombs in a lava tube while he was exploring the lava fields of Mauna Loa, the largest volcano on Earth. Singson got in touch with the Department of Land and Natural Resources, which later confirmed the bomb was in a remote part of the reserve.
In a Facebook post, he shared images of the bombs, saying he "stumbled across" the bombs while hiking. He said he believed they were dropped in either 1935 or 1942 in one of the attempts made to divert lava from flowing into the town of Hilo, on the eastern side of the island of Hawaii.
HVO has now said the bombs Singson found were dropped on December 27, 1935. Twenty of the bombs dropped were demolition bombs loaded with 355 pounds of TNT. Another 20 were pointer bombs used to aim. "The bombs were part of an effort to divert lava. A month after the 1935 eruption of Mauna Loa began, the lava pond at the base of Mauna Kea breached, sending a flow toward Hilo," the HVO said in a Facebook post, adding the lava was advancing at over one mile per day.
Thomas A Jagger, the founder of HVO, had previously considered the idea of dropping bombs onto lava to divert its flow. He asked for assistance from the army, which granted the request. The bombs were dropped just over a mile from the vent of Mouna Loa.
Image of the bomb in Mauna Loa in 1977. The Army dropped the bombs in an attempt to stop lava from threatening a nearby town. USGS PHOTO BY J. LOCKWOOD
"Events leading up to bombs penetrating the thin pāhoehoe crust of the active 1935 Humu'ula lava flow are well known to volcanologists as the first test of using explosives to stall or divert a lava flow in Hawaii," the HVO article said. "Destroying a lava conduit to redirect a flow is one of three basic diversion tactics. However, lava diversion is the subject of great debate in Hawaii, with concerns about the success of influencing a lava flow's progress and whether humans should interfere with natural processes and Pele."
Humans first floated the idea of using bombs to prevent volcanoes from damaging nearby towns and cities in 1881, according to the HVO. This was also to prevent a Mauna Loa eruption from threatening Hilo. When the volcano started erupting in 1933, the idea resurfaced."A month after the 1935 eruption began, the lava pond at the base of Mauna Kea breached, sending a flow toward Hilo... For the previous two years, Jaggar had talked about using explosives to disrupt a lava flow that might threaten Hilo. He envisioned a land expedition carrying TNT to near the vent. But Jaggar's friend, sugar chemist Guido Giacometti, suggested that Army planes might be able to drop explosive bombs more quickly and accurately."
According to the U.S. Geological Survey (USGS), subsequent assessments of the bombing attempt were mixed. USGS geologist Harold Stearns said he did not believe the bombs had been effective. Hawaii National Park Superintendent E.G. Wingate also raised doubts and wrote to Army commanders to say he was looking at possible areas for a land expedition that would be more successful at changing the flow channel.
Jagger, however, believed the effort worked, saying the rate of the lava flow had been slowed from one mile per day to around 1,000 feet per day. "I have no question that this robbing of the source tunnel slowed down the movement of the front," he wrote at the time.
The eruption ended six days after the bombs were dropped and Hilo was not destroyed by the lava. Whether the bombs helped avert disaster is still disputed today, according to the USGS.
"Events leading up to bombs penetrating the thin pāhoehoe crust of the active 1935 Humu'ula lava flow are well known to volcanologists as the first test of using explosives to stall or divert a lava flow in Hawaii," the HVO article said. "Destroying a lava conduit to redirect a flow is one of three basic diversion tactics. However, lava diversion is the subject of great debate in Hawaii, with concerns about the success of influencing a lava flow's progress and whether humans should interfere with natural processes and Pele."
Humans first floated the idea of using bombs to prevent volcanoes from damaging nearby towns and cities in 1881, according to the HVO. This was also to prevent a Mauna Loa eruption from threatening Hilo. When the volcano started erupting in 1933, the idea resurfaced."A month after the 1935 eruption began, the lava pond at the base of Mauna Kea breached, sending a flow toward Hilo... For the previous two years, Jaggar had talked about using explosives to disrupt a lava flow that might threaten Hilo. He envisioned a land expedition carrying TNT to near the vent. But Jaggar's friend, sugar chemist Guido Giacometti, suggested that Army planes might be able to drop explosive bombs more quickly and accurately."
According to the U.S. Geological Survey (USGS), subsequent assessments of the bombing attempt were mixed. USGS geologist Harold Stearns said he did not believe the bombs had been effective. Hawaii National Park Superintendent E.G. Wingate also raised doubts and wrote to Army commanders to say he was looking at possible areas for a land expedition that would be more successful at changing the flow channel.
Jagger, however, believed the effort worked, saying the rate of the lava flow had been slowed from one mile per day to around 1,000 feet per day. "I have no question that this robbing of the source tunnel slowed down the movement of the front," he wrote at the time.
The eruption ended six days after the bombs were dropped and Hilo was not destroyed by the lava. Whether the bombs helped avert disaster is still disputed today, according to the USGS.
The Army Bombed a Hawaiian Lava Flow. It Didn’t Work.
It could be tried again if the city of Hilo comes under threat, although many object to such airstrikes.
A bomb detonating on Mauna Loa near the source of a lava flow on Dec. 27, 1935. Credit...U.S. Army Air Corps
By Robin George Andrews NYT March 12, 2020
Why were two apparently unexploded bombs sticking out of a lava tube on Hawaii’s Mauna Loa? That’s what Kawika Singson, a photographer, wondered in February when he was hiking on Mauna Loa, the colossal shield volcano that rises 55,700 feet from its base below the sea to its summit.
Mr. Singson had stumbled upon relics of one of volcanology’s more quixotic disaster response plans. These devices, described in more detail recently in the U.S. Geological Survey Hawaiian Volcano Observatory’s Volcano Watch blog, were two of 40 dropped by the U.S. Army Air Corps in 1935 in an attempt to stop lava from plowing into Hilo, the most populous town on the island of Hawaii.
While Hilo was spared as the lava flow naturally lost its forward momentum, it wasn’t the last time that humanity tried to fight volcanic fire with fire of its own. History is filled with schemes to stop molten kinetic rock, and the ineffective 1935 bombing and others show that lava flows are very rarely “a force we humans can reckon with,” said Janine Krippner, a volcanologist at the Smithsonian Institution’s Global Volcanism Program.
Dense, superheated lava does whatever it wants. It certainly cannot be drained away. Few barriers can stand up to its incandescent anger. If lava threatens a harbor by the sea, pumping billions of gallons of seawater at it may slow it down, as Iceland discovered at Heimaey Island in 1973.
A pointer bomb dropped on Mauna Loa in 1935, photographed in 1977 by Jack Lockwood, a Hawaiian Volcano Observatory geologist.Credit...Jack Lockwood/U.S. Geological Survey
And then there is explosive lava diversion. As far back as 1881, it was considered to stop a lava flow headed toward Hilo. It was never tried; the pile of gunpowder remained unused, and religious conviction was widely credited with stopping the burning river.
The incendiary concept nevertheless struck a chord. Lava often travels long distances in solid tubes or in channels of its own design. Some wondered, why not sever these dangerous volcanic arteries? Bombs delivered by land could work, but aerial bombing could be more accurate and speedier.
It remained nothing more than a concept until an eruption in 1935. That December, a pond of lava breached its levees and advanced on Hilo at a rate of a mile per day. Fearing it would reach the town and its watershed, Thomas Jaggar, the founder and first director of the U.S. Geological Survey’s Hawaiian Volcano Observatory, called on the Army Air Corps. On Dec. 27, 10 Keystone B-3 and B-4 biplane bombers struck the lava flow, targeting its tubes and channels.
Half these bombs were packed with 355 pounds of TNT. The other half were not explosive, and instead designed to emit smoke so the pilots could see where the bona fide bombs landed. Mr. Singson found one of those inert devices last month.
On Jan. 2, 1936, the lava flows ceased. Dr. Jaggar was convinced the bombing worked, but other experts thought it was a coincidence. Pilots did spot several imploded lava tubes, but their collapses were insufficient to block the flow of lava. A similar operation was attempted in 1942, again to not much effect.
Despite its ineffectiveness, this explosive method of diverting lava wasn’t consigned to history. In the 1970s, a multitude of massive bombs were dropped on Mauna Loa’s ancient lava formations to investigate which features succumbed to modern bombing technologies. Spatter cones, which are volcanic mounds built up on top of a vent or fissure emitting profuse amounts of lava, were confirmed to be vulnerable to collapse, suggesting they could be targeted in the future.
And explosives have worked at least once, albeit not those dropped from the sky. During the eruption of Italy’s Mount Etna from 1991 to 1993, nearly eight tons of explosives carefully arranged by engineers were used to carve a hole in a major lava channel. Much of its molten contents then drained into a trench, which saved Zafferana Etnea, a town now of some 9,500 people.
Equipping a U.S. Army Air Corps biplane with bombs to drop on the lava flow in 1935.Credit...Kenichi Maehara, via U.S. Geological Survey
This technique isn’t without problems. As with many volcanoes around the world, said Dr. Krippner, “there’s the cultural aspect: the people’s connection with the land, and the volcanoes, and not wanting to interfere with that.” Many native Hawaiians consider the destruction of volcanic land an affront to their spiritual beliefs.
And even if it works, it cannot guarantee that successfully diverted lava won’t accidentally flow toward another important site.
Jack Lockwood, a geologist now retired from the Hawaiian Volcano Observatory and a lava diversion expert, suspects that this option will remain on the table.
He points to Mauna Loa’s 1984 eruption, which again threatened Hilo. Gov. George Ariyoshi had publicly ruled out using bombs to divert the lava. But Dr. Lockwood said that Mr. Ariyoshi’s staff asked him to draft a bombing raid contingency plan should the situation look grim.
Bombing Mauna Loa’s lava flows will always be a fraught proposition. But in a sufficiently dire situation, Dr. Lockwood said, we may again see a day when a Mauna Loa lava flow is greeted by explosive military might.
“It would require martial law, effectively, and an emergency declaration. But I suspect it would be done,” Dr. Lockwood said. Although, he added, “that might depend on the moxie of the governor, and which brickbats they were willing to tolerate.”
By Robin George Andrews NYT March 12, 2020
Why were two apparently unexploded bombs sticking out of a lava tube on Hawaii’s Mauna Loa? That’s what Kawika Singson, a photographer, wondered in February when he was hiking on Mauna Loa, the colossal shield volcano that rises 55,700 feet from its base below the sea to its summit.
Mr. Singson had stumbled upon relics of one of volcanology’s more quixotic disaster response plans. These devices, described in more detail recently in the U.S. Geological Survey Hawaiian Volcano Observatory’s Volcano Watch blog, were two of 40 dropped by the U.S. Army Air Corps in 1935 in an attempt to stop lava from plowing into Hilo, the most populous town on the island of Hawaii.
While Hilo was spared as the lava flow naturally lost its forward momentum, it wasn’t the last time that humanity tried to fight volcanic fire with fire of its own. History is filled with schemes to stop molten kinetic rock, and the ineffective 1935 bombing and others show that lava flows are very rarely “a force we humans can reckon with,” said Janine Krippner, a volcanologist at the Smithsonian Institution’s Global Volcanism Program.
Dense, superheated lava does whatever it wants. It certainly cannot be drained away. Few barriers can stand up to its incandescent anger. If lava threatens a harbor by the sea, pumping billions of gallons of seawater at it may slow it down, as Iceland discovered at Heimaey Island in 1973.
A pointer bomb dropped on Mauna Loa in 1935, photographed in 1977 by Jack Lockwood, a Hawaiian Volcano Observatory geologist.Credit...Jack Lockwood/U.S. Geological Survey
And then there is explosive lava diversion. As far back as 1881, it was considered to stop a lava flow headed toward Hilo. It was never tried; the pile of gunpowder remained unused, and religious conviction was widely credited with stopping the burning river.
The incendiary concept nevertheless struck a chord. Lava often travels long distances in solid tubes or in channels of its own design. Some wondered, why not sever these dangerous volcanic arteries? Bombs delivered by land could work, but aerial bombing could be more accurate and speedier.
It remained nothing more than a concept until an eruption in 1935. That December, a pond of lava breached its levees and advanced on Hilo at a rate of a mile per day. Fearing it would reach the town and its watershed, Thomas Jaggar, the founder and first director of the U.S. Geological Survey’s Hawaiian Volcano Observatory, called on the Army Air Corps. On Dec. 27, 10 Keystone B-3 and B-4 biplane bombers struck the lava flow, targeting its tubes and channels.
Half these bombs were packed with 355 pounds of TNT. The other half were not explosive, and instead designed to emit smoke so the pilots could see where the bona fide bombs landed. Mr. Singson found one of those inert devices last month.
On Jan. 2, 1936, the lava flows ceased. Dr. Jaggar was convinced the bombing worked, but other experts thought it was a coincidence. Pilots did spot several imploded lava tubes, but their collapses were insufficient to block the flow of lava. A similar operation was attempted in 1942, again to not much effect.
Despite its ineffectiveness, this explosive method of diverting lava wasn’t consigned to history. In the 1970s, a multitude of massive bombs were dropped on Mauna Loa’s ancient lava formations to investigate which features succumbed to modern bombing technologies. Spatter cones, which are volcanic mounds built up on top of a vent or fissure emitting profuse amounts of lava, were confirmed to be vulnerable to collapse, suggesting they could be targeted in the future.
And explosives have worked at least once, albeit not those dropped from the sky. During the eruption of Italy’s Mount Etna from 1991 to 1993, nearly eight tons of explosives carefully arranged by engineers were used to carve a hole in a major lava channel. Much of its molten contents then drained into a trench, which saved Zafferana Etnea, a town now of some 9,500 people.
Equipping a U.S. Army Air Corps biplane with bombs to drop on the lava flow in 1935.Credit...Kenichi Maehara, via U.S. Geological Survey
This technique isn’t without problems. As with many volcanoes around the world, said Dr. Krippner, “there’s the cultural aspect: the people’s connection with the land, and the volcanoes, and not wanting to interfere with that.” Many native Hawaiians consider the destruction of volcanic land an affront to their spiritual beliefs.
And even if it works, it cannot guarantee that successfully diverted lava won’t accidentally flow toward another important site.
Jack Lockwood, a geologist now retired from the Hawaiian Volcano Observatory and a lava diversion expert, suspects that this option will remain on the table.
He points to Mauna Loa’s 1984 eruption, which again threatened Hilo. Gov. George Ariyoshi had publicly ruled out using bombs to divert the lava. But Dr. Lockwood said that Mr. Ariyoshi’s staff asked him to draft a bombing raid contingency plan should the situation look grim.
Bombing Mauna Loa’s lava flows will always be a fraught proposition. But in a sufficiently dire situation, Dr. Lockwood said, we may again see a day when a Mauna Loa lava flow is greeted by explosive military might.
“It would require martial law, effectively, and an emergency declaration. But I suspect it would be done,” Dr. Lockwood said. Although, he added, “that might depend on the moxie of the governor, and which brickbats they were willing to tolerate.”
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