Sector collapse

Volcanic eruption can damage originally stable magma chambers, causing a portion of the volcano to collapse.

Hydrothermal activity is another internal cause, likely due to reactions of acid-sulfates weakening volcanic rock.

Intense weather and heavy rainfall can cause damaging erosion, increasing likelihood of collapse.

Glacial melting increases volcanic slope and decreases pore pressure, leading to sector collapse.

[3] Because sector collapse events occur suddenly and over small time periods, they are difficult to predict.

[4] Collapse ultimately occurs due to structural instability,[1] which can be determined by volcanic slope angle, composition of the volcano, deformation, and other factors.

Damage caused by collapse can create a new and different volcanic plumbing system, which could impact eruption rates.

Large overlying surface mass and the denser nature of mafic magma often prevents its rise.

Sector collapse during the 1980 eruption of Mount St. Helens [ 1 ]
Example of sector collapse: cross-section diagram of Tata Sabaya volcano (in Bolivia) (a) pre-collapse volcano, (b) after collapse, (c) new edifice built on top of collapsed old edifice
Mudflow-induced property damage caused by the 1980 Mount St. Helens sector collapse
Debris avalanche deposit of Tata Sabaya volcano's sector collapse
Approximation of Mount Rainer's Osceola collapse
Ukiyo-e depiction of 1888 Bandai Sector collapse by Japanese artist Inoue Tankei