Icebergs rushed for early showing this year. What caused it?

Thursday, March 10, 2016, 6:35 PM - Social media has been abuzz since January with pictures of icebergs off the coast of Newfoundland, but what was behind the earliest arrival of these Arctic wanderers?

Newfoundland and Labrador are famous for "Iceberg Alley" - the stretch of water along the northeast shores of the province that attracts visitors every year interested in seeing the mammoth chunks of ice floating just off-shore.

According to the provincial website, April and May are when the most icebergs show up, with late May and early June being the best time to go out to see them (to best avoid sea ice). This year, however, things have gotten off to a rather early start.

This photograph was snapped in mid-January, from Bonavista, Newfoundland, showing a large iceberg very close to shore.

An #iceberg has been spotted in Bonavista - have you seen it? pic.twitter.com/lzgV1405uA

— Iceberg Finder (@IcebergTweets) January 20, 2016

Several other icebergs showed up on social media throughout the rest of the month, and into February, including this one spotted just to the north of St. John's, NL, on February 15.

In my 43 yrs here I don't recall ever seeing a iceberg in Logy Bay in Feb. there's a massive one offshore this morn! pic.twitter.com/3UuTOhHHLq

— Chris Andrews (@shanneychris) February 15, 2016

More have shown up since.

So, what's going on here?

According to Scott Weese, senior ice forecaster for the Canadian Ice Service, there have been some anomalous winds blowing down from the north during this winter, potentially driving the icebergs further south than is typical for this time of year. However, it's not all that unusual to see icebergs in the waters off Newfoundland and Labrador in winter.

What is unusual, though, is that the icebergs that are around this season are close enough to shore for people to actually see them. Typically, if they're around in January, February or March, they're further out to sea, out of sight for anyone on land, but still a potential danger for ships traversing the Grand Banks.

What's different now?

According to Weese, an increase in on-shore winds is very likely what has caused this year's extremely early appearance of icebergs for residents of Newfoundland.

One particularly strong weather episode may have been what triggered this iceberg blitz on social media. Watch the animation below, to see what happened as Hurricane Alex made a bee-line straight for the southern tip of Greenland in January.

Credit: earth.nullschool.net with edits by S. Sutherland

The hurricane's merger with an offshore low between Newfoundland and Greenland, plus another low pressure system that tracked up the coast from the US Northeast and past Nova Scotia, appear to produce wind flow that would hustle the icebergs along towards the southeast, while creating a "dead zone" of sorts off the Avalon Peninsula - a perfect place for icebergs to cluster together for viewing. 

Iceberg charts from the North American Ice Service show how the icebergs were seen to migrate south through the middle of January.

Iceberg charts courtesy Environment Canada Ice Services. Numbers indicate the quantity of icebergs in any degree square. Dashed line is sea ice limit. Solid line is iceberg limit.

The icebergs migrate back to the northwest after the storms pass, but push back towards the Avalon Peninsula into February, increasing sightings in that area.

There has been speculation from some sources that the strong winds and warmth carried into the region by Hurricane Alex may have caused a uptick in icebergs being funneled towards Newfoundland from western Greenland.

In a blog post on the website of the American Geophysical Union, some anomalously warm conditions were recorded over Greenland in January, including the complete clearing out of sea ice in two large bays on the west coast of Greenland.

However, during a telephone interview, Scott Weese was quick to point out that most ice bergs are freed up from sea ice to the north (in Davis Strait and Baffin Bay) some 2-3 years prior to showing up along the shores of Newfoundland.

Thus, it's unlikely that these storms directly caused any more icebergs to be showing up offshore than usual, but their strong winds very likely contributed to them being visible enough to show up on social media so early in the year.

With large areas of sea ice flushing out from western Greenland and sea ice pushing down along the east coast of the island as well, it will be interesting to see what happens as we progress into spring.

Sources: CBC | Canadian Ice Service | Newfoundland and Labrador | Robert Scribbler | AGU