Tsunamis cause underwater landslides, escalating the impact.
Stephens 03 (Tim, Staff Writer @ UC Santa Cruz, “Massive tsunami sweeps Atlantic Coast in asteroid impact scenario for March 16, 2880” http://news.ucsc.edu/2003/05/355.html May 27, 2003) JM
"That's like a raging river, so as these waves cross the ocean they're going to stir up the seafloor, eroding sediments on the slopes of seamounts, and we may be able to identify more places where this has happened," Ward said. He added that the waves may also destabilize undersea slopes, causing landslides that could trigger secondary tsunamis. Ward has also done computer simulations of tsunamis generated by submarine landslides. He showed, for example, that the collapse of an unstable volcanic slope in the Canary Islands could send a massive tsunami toward the U.S. East Coast.
Asteroid Impact Climate Change
Asteroids can trigger climate change resulting in extinction
Reilly in 07 (Reilly, Michael, New Scientist, 02624079, 12/8/2007, Vol. 196, Issue 2633 6/28/2011, AH)
Asteroids and comets may also need to hit carbon-rich targets to wreak havoc on Earth's biosphere. The Manicouagan asteroid landed in ancient gneissic rocks, which contain little carbon, Arthur points out. The same is true of the Popigai impact. On the other hand, the Chicxulub crater is in a continental shelf thick with limestone, carbon-rich sediments and salt deposits. Vaporising these rocks would have sent vast amounts of sulphur dioxide into the atmosphere as well as carbon, initially triggering acid rain and cooling, followed by long-term warming. This might account for the death of more than half of all species on the planet, including the dinosaurs.
Asteroids can trigger nuclear winter-esque conditions resulting in mass extinction
Reilly in 07 (Reilly, Michael, New Scientist, 02624079, 12/8/2007, Vol. 196, Issue 2633; Accessed 6/28/2011, AH)
Why do some asteroid impacts and mega-eruptions wipe out most life on Earth while others leave barely a trace in the fossil record? IT'S a striking feature when seen from above, a circular lake 75 kilometres wide. Manicouagan, also known as the Eye of Quebec, was formed when an asteroid around 5 kilometres across struck northern Canada, gouging out a crater that was originally 100 kilometres wide. That makes Manicouagan (below right) the fifth largest impact crater on Earth, not much smaller than the 170-kilometre Chicxulub crater in Yucatán, Mexico, site of the impact that ended the reign of the dinosaurs 65 million years ago. Many blame the extinction on a "nuclear winter" caused by the dust and sulphate aerosols thrown up by the impact. Clearly the Manicouagan strike, too, must have had a similar impact. For a while it was blamed for the mass extinction that marks the end of the Triassic period 200 million years ago. But a 1992 study produced a surprise: it showed the crater is 214 million years old, too old to be the culprit.
An asteroid impact could trigger climate change, disease, famine, and war
IRWIN I. SHAPIRO et al in 10,( Harvard-Smithsonian Center for Astrophysics, Chair FAITH VILAS, MMT Observatory at Mt. Hopkins, Arizona, Vice Chair MICHAEL A’HEARN, University of Maryland, College Park, Vice Chair ANDREW F. CHENG, Johns Hopkins University Applied Physics Laboratory FRANK CULBERTSON, JR., Orbital Sciences Corporation DAVID C. JEWITT, University of California, Los Angeles STEPHEN MACKWELL, Lunar and Planetary Institute H. JAY MELOSH, Purdue University JOSEPH H. ROTHENBERG, Universal Space Network, Committee to Review Near-Earth Object Surveys and Hazard Mitigation Strategies Space Studies Board Aeronautics and Space Engineering Board Division on Engineering and Physical Sciences, THE NATIONAL ACADEMIES PRESS, http://www.fas.harvard.edu/~planets/sstewart/reprints/other/4_NEOReportDefending%20Planet%20Earth%20Prepub%202010.pdf)
Unlike most other known natural hazards to humanity, such as earthquakes, volcanic eruptions, tsunamis, hurricanes, and tornadoes, NEO impacts present a very large spread of disaster scales ranging from small property damage to global extinction events. Larger impacts may result in global climatic changes that can result in famine and disease, infrastructure failure and, potentially, societal breakdown. Smaller impacts could be misinterpreted and thereby conceivably even trigger wars. While there are numerous small incidents that present little risk to people and property, major impact events occur very infrequently. Impacts represent the extreme example of “low-probability, high-consequence” events. Although the probability of such a major impact within the next century may be small, a statistical risk of such an impact remains. Because of the nature of the impact threat, the expected fatality rate from impacts is an “actuarial” estimate based on calculations with attempted conservative assumptions. All the other estimates are based on attribution of causes of actual fatalities from ongoing threats that may change in the future.
Asteroid Impact Climate Change
Asteroid impacts cause global climate change
Dervis in 8 (Kemal Derviş has been the head of the United Nations Development Programme, the UN global development network, since August 2005., UNU World Institute for Development Economics Research, The Climate Change Challenge, 2008) DF
Some of the catastrophic effects of climate change would not, therefore, be unlike Earth being hit by an asteroid. These include, for example, the melting of the Greenland and West Antarctic ice sheets, which would result in very large sea level rises changing the world’s physical and human geography. Changes in the thermohaline circulations (the ‘conveyer belt’ of ocean heat that determines much of the earth’s climate) affecting the Gulf Stream would lead to dramatic changes in global weather patterns. Climate tipping-points could be reached, unleashing selfreinforcing multiplier feedback effects—e.g., saturated carbon sinks, releases of methane from arctic permafrost thawing—that can dramatically amplify temperature increases.
Asteroid causes climate change
BBC News in 98 [National TV and Radio services for Scotland, Wales and Northern Ireland, and over 40 local radio stations for England, BBC Online, 10 national radio stations 8 national television channel, they’re legit okay? “Meteorite is possible ice age culprit” Friday, December 11, 1998 Published at 18:16 GMT http://news.bbc.co.uk/2/hi/science/nature/233199.stm, PN]
The discovery of a 3.3-million-year-old meteorite impact site in Argentina has revealed a potential cause for the series of ice ages that has periodically frozen the Earth since that time. The new work has shown that a sharp dip in the ocean temperature occurred at the same time as dozens of species were suddenly wiped out and also when a thick layer of molten rock was formed. A meteorite impact could explain all these, as the extreme pressure at impact would melt the rocks and create a cloud of dust or smoke which would block out the sun's warming light. The impact's disturbance of the ocean circulation and atmosphere could have kick-started the global cycle of ice ages, believes Professor Peter Schultz, an impact specialist at Brown University and who led the work. An extraterrestrial object hit ocean cliffs in southeastern Argentina. "There were no glacial cycles up until this moment," he told BBC News Online. " The weather and the fauna were stable but then there was a sudden pulse recorded in the ocean sediments and coincident with the extinctions.