Krakatoa 1883 Tom Demmer Megan Hurley Sarah Noble

Krakatoa: 1883 Tom Demmer, Megan Hurley, Sarah Noble

Volcanic Eruptions • Occur near destructive margins between tectonic plates • Eruptions spew lava (called magma while inside) and ash • Lava and ash may be deadly to those on slopes and in valleys surrounding the mountain

Krakatoa • Volcanic mountain • Indonesian island of Rakata • Elevation: 2, 667 feet • Famous eruption occurred in 1883 – Eruption began on June 19, 1883 – Pre- and post-eruption events went on for months • Eruption destroyed two-thirds of the island • Eruption created the loudest sound ever observed by mankind

During the Eruption • Occurred on the morning of May 20, 1883 in Indonesia when the ash started to rise • For 2 months there were small eruptions • August 26 -27 was when the largest explosion in historical time occurred • Last day, northern 2/3 of the island collapsed

During the Eruption • Largest explosion, heard as far as Perth in Australia • Six cubic miles of rock, ash, and pumice • It was so big that debris scattered as far as Madagascar • Ash caused the formation of other islands

Location and why it happened • 130 active volcanoes on Indonesia • Arc system created by subduction • Active volcano in the Sundra straits • Krakatoa’s location makes it highly explosive

Results of Krakatoa • Tsunamis: – Only 1/3 of Krakatoa remained above sea level after the eruption – Wave up to 40 feet tall – Responsible for about 90% of casualties • Deadly Debris: – Falling tephra and hot protoclastic flows – About 2, 000 casualties sufferd severe burns

Results of Krakatoa • Atmosphere: – Fine fragments of tephra pulled into stratosphere – Decrease in temperature and exotic sky colors • Anak: – “Child of Krakatoa”

Results of Krakatoa • At least 36, 417 casualties • 165 coastal villages destroyed

References • http: //www. geology. sdsu. edu/how_volcanoes_w ork/Krakatau. html • http: //www. answers. com/topic/krakatoa • http: //www. geology. sdsu. edu/how_volcanoes_w ork/Thumblinks/Krak_symons_page. html • http: //volcano. und. nodak. edu/vwdocs/volc_imag es/southeast_asia/indonesia/krakatau_5 b. gif • http: //www. geology. sdsu. edu/how_volcanoes_w ork/subducvolc_page. html • http: //en. wikipedia. org/wiki/Krakatoa