If a average - sized asteroid lands in the sea , tsunamiswon’t be the only worry . Water vapour and sea salt thrown up by the impact could damage the ozone bed , leading to phonograph recording levels of ultraviolet radiation that could jeopardise humanity .
“ This propose young exit you could have with sea impingement that people had n’t thought of before , ” saysBrian Toonof the University of Colorado at Boulder , who was not involved in the piece of work .
Elisabetta Pierazzoof the Planetary Science Institute in Tucson , Arizona , and fellow used a spherical climate model to study how water vaporization and sea salt thrown up from an shock will pretend ozone levels for years after the result .
They focused on average - sized asteroids , either 500 meters or 1 kilometer wide . To particular date , 818 asteroids that are at least 1 kilometer widehave been discovered on orbits that could take them cheeseparing to Earth .
Olympic Splash
These physical object are on area that give them a very small-scale chance of hitting Earth in the near future . However , estimate of the asteroid population suggest dozens more have yet to be found , with unknown area that could cross with the Earth .
To get a signified of how much weewee might be jettisoned into the atmosphere if these asteroid hit the sea , the team modeled what would fall out if they reached Earth ’s air at a clip of 18 kilometers per moment , an average speed gestate for a cheeseparing - Earth objective , and hit the ocean in the northern hemisphere at a 45 - level angle .
As expected , the simulations showed that the larger , 1 - km asteroid create the bigger splash , shed 42 trillion kilograms of water and vapor – enough to meet 16 million Olympian - sized swimming syndicate – across an expanse more than 1000 kilometers wide-cut and up to hundreds of kilometers above the Earth ’s surface .
Engulfing Earth
Once in the atmospheric state , the water , together with chemical compound containing chlorine and bromine from vaporized sea salts , destroyed ozone above the Earth ’s atmosphere at a much fast rate than it is naturally created .
Some simulated shock created depletions that were still felt across the whole Earth a year later . “ It will produce an ozone cakehole that will engulf the entire Earth , ” Pierazzo says .
The longest durable and most stern depletion – a deletion of more than 70 per penny in ozone levels – occurred over much of the northerly cerebral hemisphere .
That ’s a far enceinte hole than the one that was above the South Pole in 1993 , when Earth ’s ozone bed was at its slender . The resulting ultraviolet - radiation levels would be higher than anywhere on Earth today , the team write , present a Modern hazard for human civilization .
Dry Hits
While people may be able to protect themselves from the increased threat of erythema solare , the intense UV light could also impress our intellectual nourishment supply by prejudicial plant life and the phytoplankton that represent the bottom of the sea ’s intellectual nourishment mountain range . “ That is enough to really cause problems for our civilization , ” Pierazzo says .
Better understanding these effect could serve us prepare in the effect of an impingement . For example people could plant crops more resistant to UV irradiation , she bestow .
Toon notes that encroachment on country or shallow water may at last do more wrong by kicking up dust that could importantly darken skies and curb plant life growth . Pierazzo is now act upon on a model to evaluate how asteroid that hit ironical land would affect the atm .
asteroidsEarthmeteorMeteorsSpacetsunamis
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