View of the lava lake within Halema‘uma‘u from the FTIR spectromete...

View of the lava lake within Halema‘uma‘u Crater from the FTIR spectrometer monitoring location. At Hawaiian volcanoes, magma ascends from the mantle more than 60 km (about 40 mi) below the surface, to a reservoir less than 2 km (about 1.2 mi) deep. As the pressure decreases, the gases dissolved in the magma bubble out and escape. Magma continues to rise through a shallow conduit to the Halema‘uma‘u lava lake, where it continues to degas (the blue haze is indicative of sulfur gases).