Fig. 6
From: Automated tracking of lava lake level using thermal images at Kīlauea Volcano, Hawai’i
Multiparameter plot of lava level and ground tilt fluctuations at Kīlauea in mid-2014. a. Automated result for lava level (hourly average), converted to absolute elevation using the linear regression shown in Fig. 4. b. Summit ground tilt from the UWE tiltmeter, approximately 2 km from the lava lake in Halema‘uma‘u. Increasing and decreasing values imply inflation and deflation, respectively. c. Number of located earthquakes per day in the upper East Rift Zone. The strong correlation between lava level and ground tilt suggests the lake acts as an effective “pressure gauge” of the summit magma reservoir. Elevated lava levels (and tilt) were present during late April and early May, culminating in an abrupt drop in lava level and summit deflation on May 10, which preceded elevated earthquake activity for the next several days. Preliminary interpretation suggests that a small intrusion occurred in response to the elevated summit pressure, dropping the level of the lava in the lake. Episodes of intense spattering are visible as transient spikes in lava level, followed by rapid drops (a real drop in lava lake level due to gas release)