Tiltmeters measure tiny changes that can have big consequences
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. USGS photos.
Sources/Usage
Public Domain.