posted on Jul, 16 2011 @ 04:52 AM
A VEI4 is to small to do anything to effect the climate
You need a a long term eruption of a VEI6or above to to start affecting the climate. or a couple VEI5s
They also need to be high in Tephra Ash and high in gaseous sulfur compounds, chiefly sulfur dioxide,
in the last 100 years we have had only one Pinatubo.
Since 1000 AD
* Pinatubo, island of Luzon, Philippines; 1991, Jun 15; VEI 6; 6 to 16 cubic kilometers (1.4 to 3.8 cu mi) of tephra an estimated 20 million tons
of sulfur dioxide were emitted
* Novarupta, Alaska Peninsula; 1912, Jun 6; VEI 6; 13 to 15 cubic kilometers (3.1 to 3.6 cu mi) of lava
* Santa Maria, Guatemala; 1902, Oct 24; VEI 6; 20 cubic kilometres (4.8 cu mi) of tephra
* Krakatoa, Indonesia; 1883, August 26–27; VEI 6; 21 cubic kilometres (5.0 cu mi) of tephra
* Mount Tambora, Lesser Sunda Islands, Indonesia; 1815, Apr 10; VEI 7; 150 cubic kilometres (36 cu mi) of tephra;[5] an estimated 200 million tons
of sulfur dioxide were emitted, produced the "Year Without a Summer"
* Grímsvötn, Northeastern Iceland; 1783–1785; Laki; 1783–1784; VEI 6; 14 cubic kilometers of lava, an estimated 120 million tons of sulfur
dioxide were emitted, produced a Volcanic winter, 1783, on the North Hemisphere.
* Long Island (Papua New Guinea), Northeast of New Guinea; 1660 ±20; VEI 6; 30 cubic kilometers (7.2 cu mi) of tephra.
* Kolumbo, Santorini, Greece; 1650, Sep 27; VEI 6; 60 cubic kilometers (14.4 cu mi) of tephra.
* Huaynaputina, Peru; 1600, Feb 19; VEI 6; 30 cubic kilometres (7.2 cu mi) of tephra.
* Billy Mitchell, Bougainville Island, Papua New Guinea; 1580 ±20; VEI 6; 14 cubic kilometres (3.4 cu mi) of tephra.
* Bárðarbunga, Northeastern Iceland; 1477; VEI 6; 10 cubic kilometres (2.4 cu mi) of tephra.
* 1452-53 ice core event, New Hebrides arc, Vanuatu; location of this eruption in the South Pacific is uncertain; only pyroclastic flows are found
at Kuwae; 36 to 96 cubic kilometers (8.6 to 23.0 cu mi) of tephra; 175-700 million tons of sulfuric acid.
* Quilotoa, Ecuador; 1280(?); VEI 6; 21 cubic kilometres (5.0 cu mi) of tephra.
* 1258 ice core event, tropics; 200 to 800 cubic kilometers (48.0 to 191.9 cu mi) of tephra.