Which earthquake monitoring method allowed the Hawaii Volcanoes Observatory to detect magma migration and warn residents and homeowners at Leilani Estates?

Various techniques are used to detect lava nad earthquake movements.

Explanation:

Leilani Estates is a place located at the tip of the Eastern Island of Hawaii bordered by a forest reserve. It is directly located on a stretch of the lower east rift zone of Kilauea Volcano in lava flood zone one. The area remains to be close and the residents are discouraged to approach the area perimeter and the government has put a ban of 5000 dollars for the same. The use of GPS devices and Tilt meters are allowed by the observatorie to track the lava flow. Gas monitoring is also an important part of the exercise. As there are more than 100 stations for the field observatory and record data in the form of radio signals.