Asteroid ocean strike 'could strip away ozone layer'

A medium-sized asteroid plunging into the ocean would destroy much of the ozone layer, leaving the Earth exposed to dangerous levels of ultraviolet radiation, it was claimed today.





The impact from a space rock 500 metres to one kilometre in diameter would send vast amounts of water into the atmosphere, according to US expert Dr Elisabetta Pierazzo.



Seawater chemicals such as chloride and bromide would strip away significant amounts of ozone, which provides a shield against harmful sun rays.



The result would be a huge spike in ultraviolet (UV) radiation levels at the Earth's surface.



People with fair skins would find their skin burning after just a few minutes of sun exposure.



Farmers would have difficulty growing crops, and rates of skin cancer and cataracts would be likely to rise.



Previous research looking at the effects of an oceanic asteroid impact has focused on the danger of tsunamis.



Dr Pierazzo's new work, published in the journal Earth and Planetary Science Letters, used computer simulations to model the effects on atmospheric ozone.



She tested two impact scenarios, involving a 500 metre and kilometre diameter asteroid.



"The results suggest that mid-latitude oceanic impact of one kilometre asteroids can produce significant global perturbation of upper atmospheric chemistry, including multi-year global ozone depletion comparable to record ozone holes recorded in the mid 1990s," said Dr Pierazzo, from the Planetary Science Institute in Tucson, Arizona.



"The removal of a significant amount of ozone in the upper atmosphere for an extended period of time can have important biological repercussions at the Earth's surface as a consequence of increase in surface UV-B irradiance. These include increased incidence of erythema (skin reddening), cortical cataracts, changes in plant growth and changes in molecular DNA."



People may be forced to avoid direct sunlight to protect themselves against the harmful UV rays, she added.



UV intensity is measured by the ultraviolet index (UVI), with levels of 10 or above assumed to be dangerous.



The highest UVI recorded on Earth so far has been 20, said Dr Pierazzo. But a 500-metre asteroid crashing into an ocean could see UVI jump to values above 20 for several months in the northern subtropics.



A one kilometre impact would see UVI soar to 56, rising above 20 for around two years in both the northern and southern hemispheres.



"A level of 56 has never been recorded before, so we are not sure what it is going to do," said Dr Pierazzo. "It would be producing major sunburn. We could stay inside to protect ourselves, but if you go outside during daylight hours you would burn. You would have to go outside at night, after sunset, to avoid major damage."



Assuming there is enough warning, farmers could reduce the effects of the impact by planting crops with a higher UV tolerance, she said.



Food could also be stored to ensure supplies during a few years of poor productivity.

Sport
Laura Trott with her gold
Commonwealth GamesJust 48 hours earlier cyclist was under the care of a doctor
Life and Style
Upright, everything’s all right (to a point): remaining on one’s feet has its health benefits – though in moderation
HealthIf sitting is bad for your health, what happens when you stay on your feet for a whole month?
Arts and Entertainment
Peter Griffin holds forth in The Simpsons Family Guy crossover episode
arts + ents
News
Orville and Keith Harris. He covered up his condition by getting people to read out scripts to him
People
PROMOTED VIDEO
Sport
France striker Loic Remy
sportThe QPR striker flew to Boston earlier in the week to complete deal
Arts and Entertainment
Gal Gadot as Wonder Woman
arts + entsFilmmaker posted a picture of Israeli actress Gal Gadot on Twitter
Sport
Vincenzo Nibali rides into Paris on the final stage of the 2014 Tour de France
Tour de FranceVincenzo Nibali is first Italian winner since Marco Pantani in 1998
News
Bryan had a bracelet given to him by his late father stolen during the raid
people
Arts and Entertainment
Chris Pratt stars in Guardians of the Galaxy
arts + ents
Arts and Entertainment
Pedro Pascal gives a weird look at the camera in the blooper reel
arts + entsPrince Oberyn nearly sets himself on fire with a flaming torch
News
Danny Nickerson, 6, has received 15,000 cards and presents from well-wishers around the world
newsDanny loves to see his name on paper, so his mother put out a request for cards - it went viral
Arts and Entertainment
Zoe Saldana stars in this summer's big hope Guardians of the Galaxy
filmHollywood's summer blockbusters are no longer money-spinners
Sport
Red Bull Racing's Australian driver Daniel Ricciardo (C) celebrates with Scuderia Ferrari's Spanish driver Fernando Alonso (L) and Mercedes' British driver Lewis Hamilton
sport
Arts and Entertainment
comedy
Arts and Entertainment
Public vote: Art Everywhere poster in a bus shelter featuring John Hoyland
art
Arts and Entertainment
Judd Apatow’s make-it-up-as-you-go-along approach is ideal for comedies about stoners and slackers slouching towards adulthood
filmComedy was dominated by the romcom at its most insufferable
Sport
Tour de France competitor Bartosz Huzarski’s legs have highlighted the gruelling nature of the race, after he posted a picture on Facebook showing extremely prominent veins stretching from his feet and all the way up his legs
Commonwealth Games
Life and Style
Elle Kaye demonstrates the art of taxidermy
food + drinkFood revolution taken a step further in new ‘edible taxidermy’ class
News
A rub on the tummy sprang Casey back to life
video
Sport
Halsall broke her personal best in the 50m butterfly
Commonwealth GamesEnglish swimmer is reborn after disastrous time at London 2012
Arts and Entertainment
O'Shaughnessy pictured at the Unicorn Theatre in London
tvFiona O'Shaughnessy explains where she ends and her strange and wonderful character begins
News
ebookA unique anthology of reporting and analysis of a crucial period of history
Life and Style
Workers in Seattle are paid 100 times as much as workers in Bangladesh
fashionSeattle company lets customers create their own clothes, then click 'buy' and wait for delivery
Arts and Entertainment
Red Bastard: Where self-realisation is delivered through monstrous clowning and audience interaction
comedy
Arts and Entertainment
booksForget the Man Booker longlist, Literary Editor Katy Guest offers her alternative picks
Voices
The Express offices in the 1930s when writers (such as Orwell) were paid around £2 weekly
voicesWebsites offering your ebooks for nothing is only the latest disrespect the modern writer is subjected to, says DJ Taylor
Life and Style
A cut above: Katy Guest at The Ginger Pig
food + drinkThe Ginger Pig's hands-on approach to primary cuts
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Data Analyst

£30000 per annum: Ashdown Group: A highly reputable software house is looking ...

Application Support Analyst / Junior SQL Server DBA

£40000 - £45000 per annum: Ashdown Group: An established professional services...

Commercial Litigation

Highly Attractive Salary: Austen Lloyd: CITY - SENIOR COMMERCIAL LITIGATION SO...

BI Developer - Sheffield - £35,000 ~ £40,000 DOE

£35000 - £40000 per annum + competitive: Progressive Recruitment: My client is...

Day In a Page

A new Russian revolution: Cracks start to appear in Putin’s Kremlin power bloc

A new Russian revolution

Cracks start to appear in Putin’s Kremlin power bloc
Eugene de Kock: Apartheid’s sadistic killer that his country cannot forgive

Apartheid’s sadistic killer that his country cannot forgive

The debate rages in South Africa over whether Eugene de Kock should ever be released from jail
Standing my ground: If sitting is bad for your health, what happens when you stay on your feet for a whole month?

Standing my ground

If sitting is bad for your health, what happens when you stay on your feet for a whole month?
Commonwealth Games 2014: Dai Greene prays for chance to rebuild after injury agony

Greene prays for chance to rebuild after injury agony

Welsh hurdler was World, European and Commonwealth champion, but then the injuries crept in
Israel-Gaza conflict: Secret report helps Israelis to hide facts

Patrick Cockburn: Secret report helps Israel to hide facts

The slickness of Israel's spokesmen is rooted in directions set down by pollster Frank Luntz
The man who dared to go on holiday

The man who dared to go on holiday

New York's mayor has taken a vacation - in a nation that has still to enforce paid leave, it caused quite a stir, reports Rupert Cornwell
Best comedians: How the professionals go about their funny business, from Sarah Millican to Marcus Brigstocke

Best comedians: How the professionals go about their funny business

For all those wanting to know how stand-ups keep standing, here are some of the best moments
The Guest List 2014: Forget the Man Booker longlist, Literary Editor Katy Guest offers her alternative picks

The Guest List 2014

Forget the Man Booker longlist, Literary Editor Katy Guest offers her alternative picks
Jokes on Hollywood: 'With comedy film audiences shrinking, it’s time to move on'

Jokes on Hollywood

With comedy film audiences shrinking, it’s time to move on
It's the best of British art... but not all is on display

It's the best of British art... but not all is on display

Voted for by the British public, the artworks on Art Everywhere posters may be the only place where they can be seen
Critic claims 'I was the inspiration for Blanche DuBois'

Critic claims 'I was the inspiration for Blanche DuBois'

Blanche Marvin reveals how Tennessee Williams used her name and an off-the-cuff remark to create an iconic character
Sometimes it's hard to be a literary novelist

Sometimes it's hard to be a literary novelist

Websites offering your ebooks for nothing is only the latest disrespect the modern writer is subjected to, says DJ Taylor
Edinburgh Fringe 2014: The comedy highlights, from Bridget Christie to Jack Dee

Edinburgh Fringe 2014

The comedy highlights, from Bridget Christie to Jack Dee
Dame Jenny Abramsky: 'We have to rethink. If not, museums and parks will close'

Dame Jenny Abramsky: 'We have to rethink. If not, museums and parks will close'

The woman stepping down as chair of the Heritage Lottery Fund is worried