#interferogram

Moving lava

The photo is an interferogram, created on May1 by superimposing satellite radar data of today with that from some time ago and depicting the ground deformation changes as colourful swaths. It depicts the lava moving down Kilauea's East Rift Zone on the Big Island of Hawaii, following from the recent collapse of the floor of Puʻu ʻŌʻō crater (which has been gushing lava on and off since 1983) and a series of earthquakes.

The pattern near Makaopuhi and Puʻu ʻŌʻō imply withdrawing magma, and the fringes in the lower rift zone show the swelling as it shifts downslope and pools there. The absence of colour at the summit tells us that the magma chamber up there is not currently involved but the overflow the other day at the erupting crater may be related to the shifting magma (see https://bit.ly/2rjmCzd and https://bit.ly/2KwQYHf).

Ground deformation is one of the three main means of volcano monitoring and assessment for imminent eruption risk, along with earthquake patterns and shifts in the amounts and composition of released volcanic gases. All carefully assessed against the best baselines of background activity available.

Loz

Image credit: USGS/ESA