17 May 2010

Geo-image Accretionary Wedge

Posted by Jessica Ball

My geo-photo of choice is a bit of interplay between the forces of geology and biology: an ohi’a shoot growing from a crack of a lava flow on the flank of Mauna Ulu, on the Big Island of Hawaii. The photo is significant to me for a number of reasons: This was my second trip to Hawaii, but the first time I’d had a chance to learn the techniques of volcano monitoring; it was also the first time that I’d really begun to understand the workings of an active volcano. This hike, part of a volcanology field course run by UH Hilo, took us up a lava channel to the summit of Mauna Ulu, through more forms of basaltic lava than I’d ever imagined existed. It was fascinating stuff. It was also a surprise to come across little enclaves of plants every so often – the first colonizers of a totally inhospitable environment. The contrast of the green leaves of the ohi’a and ferns against the dark lava flows was striking, and quite beautiful. 
This photo reminds me that even the destruction caused by volcanoes doesn’t last forever. Tomorrow’s anniversary – that of the May 18, 1980 eruption of Mt. St. Helens – brings to mind the amazing transformation that the blast zone has undergone in the 30 years since the event. The same persistent forces were at work on Mauna Ulu since its eruption ended in 1974, and the patches of life that I saw in a lifeless terrain were a subtle reminder of the processes of change.