User:Penitentes/Lava diversion

Lava diversion methods are used to alter the speed and course of lava flows so as to reduce their detrimental effects, such as the destruction of human settlements and infrastructure.

Attempts have been made to divert lava flows since...

Most efforts to divert lava flows have been unsuccessful. Those that succeeded did so only with large expenditures of effort, money, and time.

Challenges
The Hawaiian Volcano Observatory stresses that the successful lava diversion efforts in Italy and Iceland "required costly and time-consuming efforts for months at a time".

Lava is too dense for common barrier methods, such as the jersey barrier, to be effective. A lava flow diverted away from one area may threaten another area as a consequence.

Lava diversion also faces opposition for cultural or religious reasons.

Pre-20th century
In 1669, Mount Etna

In 1881, Mauna Loa erupted on the island of Hawaii and lava flows threatened the community of Hilo. Residents attempted to stem the flow with walls built out of rock. When those failed, local authorities considered using a pile of gunpowder to cause an explosion at the head of the lava flow. The eruption ceased before such attempts became necessary.

20th century
In November of 1935, a summit eruption began at Mauna Loa. A vent opened on the mountain's northern flanks, and a pāhoehoe lava flow ensued. The flow stalled in a flat area of terrain for several weeks, but eventually it reached steeper ground, where it traveled up to 1 mi per day and threatened to impinge upon the Wailuku River (part of the water supply for the city of Hilo). Thomas Jaggar, the founder and director of the Hawaiian Volcano Observatory, called on the Army Air Corps to bomb the lava flow in the hopes of... collapsing lava tubes and reducing the ability of the flow to advance.

In 1942 the method was repeated.

In 1959 walls built at Mauna Loa https://rd.springer.com/article/10.1007/BF02599351

In 1973 the Icelandic harbor of... explosives were planned

In 1983 trials at Etna

In 1984 Hilo was threatened again, and bombing was considered as a contingency plan.

In 1992 lava diversion efforts occurred on Mount Etna

21st century
In 2018, Sinabung lava diversion channels https://thediplomat.com/2018/03/living-in-the-shadow-of-mount-sinabung/

In 2021 in La Palma earthmoving efforts were unsuccessful https://english.elpais.com/spain/2021-09-22/despite-diversion-efforts-wall-of-lava-reaches-more-homes-after-la-palma-volcano-eruption.html

In 2021, Eldfell in Iceland https://www.forbes.com/sites/davidbressan/2021/05/16/iceland-to-build-defensive-wall-against-lava/?sh=64449d851318

Following the late 2022 eruption of Mauna Loa, as lava flows threatened to cross Daniel K. Inouye Highway/Saddle Road officials discussed the possibility of diverting the flow. Officials and experts such as governor David Ige and Hawaiian Volcano Observatory scientist Ken Hon, deemed such efforts difficult to impossible given the terrain and the volume of lava. The lava flows ultimately never reached the highway.