Volcanoes: our unpredictable, often dangerous, reminder of a planet still in formation [1]

Martin William-South China Morning Post-Sunday July 21,2013

These dramatic formations are the most vivid reminder that our planet is a work in progress

Roaming across a satellite crater of Tangkuban Perahu - the "Upside Down Boat" volcano in west Java, Indonesia - gives some inkling of the awesome power in the earth beneath. It's a primeval place, an expanse of yellowish and sullen red rock forming a gently sloping depression amid jungle. Steam rises from a perpetually boiling spring, hot sulphurous gases emerge from vents.

The larger, main crater is above. Here, a column of steamy gases surges skywards, thrust from an opening at such pressure that, even from some 200 metres above, it sounds like a powerful waterfall. A road leads to the rim, where a path passes simple cafes and souvenir stalls. Hundreds of visitors arrive during the morning, as if this is as safe as a regular tourist spot.

Yet the volcano is dangerous, subject to phreatic eruptions in which water superheats to become steam that blasts rock apart. Just weeks after my visit, a phreatic eruption created a plume of ash that covered the car park, and closed the volcano to visitors. In May, a more violent phreatic eruption killed five climbers on the Mayon volcano, in the Philippines.

Read More: http://www.scmp.com/lifestyle/technology/article/1287093/volcanoes-our-unpredictable-often-dangerous-reminder-planet [2]