Global warming is increasing the number of icebergs in the Southern Hemisphere

At least two clusters of more than 100 icebergs have split off their Antarctic ice shelf and are headed towards New Zealand, prompting authorities to issue navigation warnings for the southern coast of the island nation.

Scientists say the icebergs are remnants of the Ross Ice Shelf that broke off from Antarctica a decade ago. One of the largest chunks - nearly a mile long - was seen off the Macquarie Island coast 280 miles from New Zealand earlier this month. As the mass moves north and through warmer waters it continues to melt and break up into smaller pieces.

These floating catastrophes come at a time when Antarctic tourism, much of it Chile-based, is flourishing. And the ever-growing presence of icebergs is complicating business.

Data developed by the Antarctic and Southern Ocean Coalition (ASOC) confirms that nearly 50,000 tourists visited the Antarctic in the summer of 2007/2008, up from 4,600 summer of 1990/1991.

A recent penguin viewing expedition (costing anywhere from US$14,000-US$23,000) was stuck in the Antarctic for five days due to shifting ice. In November 2007 the MS Explorer, a cruise ship carrying more than 150 passengers and crew sank near the Antarctic Peninsula after hitting an iceberg.

The growing concern over the effect and safety of tourism in the region has prompted countries from the U.S. to New Zealand to call for regulation of the industry.

ASOC has been calling for regulation of tourism in the Antarctic for years and provides information to tourists planning on visiting the area on their website asoc.org.

Smaller sized icebergs do not register in satellite images, and as they gradually shrink even on-board radar may have difficulty spotting them. The difficulty in seeing them combined with their mass, 90 percent of which is underwater, make them all the more dangerous to ships.

Australian glaciologist Neal Young says the icebergs now floating towards New Zealand are spread out over a large area. “Thanks to satellite images, we know the icebergs are spread out in an area 600 by 440 miles,” said Young. “They're following the same tracks now up towards New Zealand. Whether they make it up to the South Island or not is difficult to tell."

It is unusual to see icebergs off the coast of New Zealand, though scientists believe warmer oceans are likely to increase the trend. Cooler temperatures in southern New Zealand and ocean currents combined to allow the ice to travel north.

The increase in Antarctic ice melting (ST, Nov 23) and rising ocean temperatures have scientists worried about continuing degradation in Antarctica. "If the current trends in global warming were to continue, I would anticipate seeing more icebergs and the large ice shelves breaking up," said Young.

The 2008 Greenhouse Gas Bulletin released by the World Meteorological Organization (WMO) this week says greenhouse gases are still growing exponentially and hit their highest level in 2008.

“The warming of the planet is not just proved by rising temperatures,” said Michael Jarraud secretary general of WMO. “This is not just hypothesis. These are situations we can observe and measure.”

Chunks of ice breaking off the Antarctic are not just a danger to tourism cruisers and ships as they float in the oceans, says Chilean glaciologist Ricardo Jaña. They also destroy ecosystems as they go through the slow process of dislodging from the continent.

“They are like bulldozers moving with the current,” said Jaña. “As masses of ice break off on the surface they are still attached underwater. The grinding against the continent erodes the ocean floor, where “they destroy all the established species.” Jaña added that the melting freshwater icebergs changes salt level of the ocean, which can also harm marine life.


SOURCES: LA TERCERA, ASOC.org, AP, WMO, MERCOPRESS
By Pamela Morales ( This e-mail address is being protected from spambots. You need JavaScript enabled to view it )

 

Pamela was born in Osorno Chile but grew up gringa in Cleveland, Ohio. After spending four wonderful years in Toronto she had a choice: Stay on the corporate train headed to Phoenix or get off. She (and her fantastic husband) closed their eyes, sold all their belongings, and jumped. Following three months of delightful do-nothingness she joined the Santiago Times to pursue her interest in writing.