a tiltmeter is ready for installation
By Hawaiian Volcano Observatory
2018 (approx.)
Detailed Description
On the right, a tiltmeter is ready for installation in a shallow borehole. On the left, the tiltmeter is located at the bottom of a 3 to 4 m (10 to 15 ft) borehole lined with a metal casing. The tiltmeter is surrounded by sand to secure it within the borehole so that it does not touch the casing.
Sources/Usage
Public Domain.