The 30 m class ground-based Giant Magellan Telescope under construction at Las Campanas Observatory in Chile’s Atacama Desert has been equipped with a seismic protection design validated by an independent review panel. The region is prone to high tectonic activity, necessitating installation of a seismic isolation system to protect the 22-story rotating observatory and seven of the world’s largest monolithic mirrors from being damaged by earthquakes.

The seismic isolation system needs to not only protect the structures from collapse, as recently occurred due to A circular array of 24 single friction pendulum isolators is located under the telescope’s pier for support and to protect optical components and instruments from active ground motion caused by major earthquakes. Source: Giant Magellan Telescope – GMTO Corporationcable failures at the Arecibo Observatory in Puerto Rico, but also to prevent the structure and fragile optical components inside from requiring repair. The Giant Magellan Telescope system will only engage during earthquakes that exceed a magnitude of approximately 5, and extreme earthquakes that will typically occur on a one- to two-year time scale.

The protection system is a circular array of 24 single friction pendulum isolators that support the telescope and its pier and protect optical components and instruments from active ground motion caused by a major earthquake. A hydraulic system has been engineered to return the 6,200 metric ton telescope structure to its original resting and operational position following a major earthquake. A return to operations can be realized within hours to weeks, depending on the magnitude of a seismic event.