Monday, November 18, 2013

Moonlight on Lava: What Makes it Shine?

When the moon is bright, Kilauea's newest lava fields take on an almost supernatural appearance as the strange shapes of cooling lava shine like silver glitter. The change from the lava's daytime appreance is quite dramatic, and our guests always notice it with a sense of delight.
 
Moonlit Lava Walks
Moonlit lava's silvery reflection


It's difficult to capture in a photograph, but the surface of the lava flow reflects a lot of light, and is especially sparkly in strong moonlight. 

Lava Hikes by moonlight
Moonlight on the 2010 flow field

This silver shine is caused by silica, one of major mineral components of lava. There are several different types of lava made up of varying proportions of different minerals and gasses. All of the lavas from Hawai'i's volcanoes are basaltic. Basalts have a lower proportion of silica than other magmas, but sometimes it is more visible in certain types of basalt, because it rises to the surface of cooling lava. 



Geology on our lava walks
Silvery folds of new pahoehoe in afternoon light

Pahoehoe is the most common type on the Kalapana coastal flow fields. As it cools, silica often creates a glassy, shiny layer on the surface. This layer is ephemeral and erodes away with age, leaving the rock with a darker, duller appearance. 

It's a pretty impressive sight to see the silvery sheen of Kilauea's new lava, especially in the moonlight! We've had some great weather over the last week and the moon is high and bright.

Come enjoy it with us on our Lava, Wine and Stars Tour. For reservations click HERE.

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