Double volcanic eruption in Eastern Russia   This 7 March 2005 Envisat MERIS image shows the unusual phenomenon of the simultaneous eruption of two stratovolcanoes, Kliuchevskoi and Shiveluch (or Sheveluch) on Russia's Kamchatka Peninsula. Stratovolcanoes are formed of alternating layers of pyroclastic materials and subordinate lavas. They have conical shapes and are built up by multiple eruptions. The lava produced during stratovolcano eruptions is typically andesitic, with fine grains and dark colour. Andesitic eruptions tend to be explosive, producing pyroclastic materials and in some cases 'ignimbrites' - fist-sized pumice fragments. The Reduced Resolution mode image has a 300 metre resolution.   This detail from a larger MERIS image acquired 7 March 2005 shows the two ash plumes from simultaneous eruptions of the Kliuchevskoi and Shiveluch (or Sheveluch) stratovolcanoes on Russia's Kamchatka Peninsula. Eruptions are relatively common here, with around 60 active volcanoes in the vicinity. Release date: 22 February 2008