Trigger

Trigger (起爆剤, Kibakuzai^?, lit. "Triggering Explosive") is the name used to refer to the Small Scale Induction-Style Active Volcano Controlling Device (小規模誘発式活火山制御装置, Shōkibo Yūhatsu-shiki Kakkazan Seigyosōchi^?), technology developed by the United States military for the purpose of inducing controlled volcanic eruptions.

Though seemingly only a part of Gremlin's plan in Hawaii, it later becomes clear that its purpose was greatly downplayed for the purpose of deception.

Appearance

The individual devices look like drums with four legs, which spread out like a cross and are then securely affixed to the ground with special stakes as support, to be positioned in strategic locations around a volcano. There are no cables, as each individual device is timer controlled and a totally isolated system.

Principles

It was developed by the military and is primarily based in Oahu, Hawaii. As the official name suggests, it is a device that control the activities of an active volcano. Its purpose is not to stop an eruption from occurring, but to distribute the energy to minimize the destructive properties from the sheer force of an eruption.

It uses a special combination of explosives set up in strategic points around an active volcano and applying stimuli in various stages to the underground magma to regulate it and cause small scale eruptions, hence the name. The device's stimuli is via sending powerful vibrations underground from multiple angles at once.

By letting pressure escape before a major eruption occurs, the worst-case scenario can be avoided, mitigating overall fatalities and economic damage from avalanches, pyroclastic flows and ash clouds. However, with proper manipulation, the technology can also be used to incite a destructive eruption.

Chronology

Shinyaku Toaru Majutsu no Index

Hawaii Invasion Arc

Main article: Hawaii Invasion Arc

The Trigger played an important role in the beginning of the events in Hawaii, however, its full importance was revealed only at the end.

Roberto Katze used the Imperial Package to determine the queer circumstances surrounding his government, and discovered, more importantly, the fact people unrelated to Trigger were somehow trying to find information regarding it. Later, he discovered that Trigger was in Oahu, at Pearl Harbor. After joining Leivinia Birdway and Kamijou Touma's group with Accelerator, they determined that Gremlin's goal was to strike the United States of America (and by proxy the Science side), shaming it in international affairs and destablizing its economy, by inducing an eruption of Kilauea and triggering a chain reaction with the other volcanoes, creating a huge catastrophe and possibly killing hundreds of thousands of people from several nations.

Kilauea's eruption marks the beginning of the invasion.

With this plot in mind, Roberto, Leivinia, Misaka Mikoto, Accelerator and Touma went inside Pearl Harbor to secure the Trigger. After much trouble with Saronia A. Irivika, it was discovered that Trigger had already been deployed. In the Volcanoes National Park in the island of Hawaii, Hamazura Shiage, Kuroyoru Umidori and Misaka Worst, found that Trigger was already set up and activating. Despite Hamazura's best efforts, they were forced to retreat as Kilauea, and only Kilauea, erupts.

Kilauea spewed volcanic ash into the atmosphere, spreading forth in every direction, a queer sign that Touma and company seemed to overlook, as thick lava flows should have been expected. Nevertheless, the invasion of the Hawaiian Islands began in earnest as Trident and their occult allies from Gremlin commenced their attack on American soil.