During the week of January 26, 2015, the Thirty Meter Telescope performed a series of "shake tests" in El Segundo, California. A major earthquake was simulated to confirm that the telescope's mirror segments would survive without damage.
A mirror segment was first shaken vertically. The aluminum mirror segment used in the tests had the same mass properties as the actual segments that will be used in TMT's construction.
The mirror segment was then shaken horizontally. The intensity of the shaking simulated the worst estimated earthquake that would be expected in Hawaii over a 200 year period.
The Primary Segment Assembly passed the tests extremely well, as shown in the video below: