A recent slide on Mount Steele could be the largest ever in the recorded history of the Yukon.

Mount Steele, which stands 5,067 metres tall (16,624 feet) and is the fifth-highest peak in Canada, recently had two slides take place in the same area on the northern face of the mountain.

The second slide was by far the larger of the two and took place on July 24, two days after the original slide, and was large enough to generate a seismic signal that could be picked up around the world. The slide was the equivalent of a 3.5 magnitude earthquake.

'The first one was still very impressive and terrifying, but the second slide was just massive,' Panya Lipovsky, a surficial geologist for the Yukon Geological Survey, said in an interview Tuesday.

Lipovsky flew over the slide area on Aug. 2 in a fixed-wing aircraft to survey the site and see how much it had changed since initial reports. Through data compiled by photographs, geologists have been able to estimate rough dimensions of the debris and the distance it travelled.

Based on aerial figures, the horizontal distance the debris field spanned was approximately seven kilometres long, and dropped a vertical distance of approximately 2,500 metres down to the glacier below.

The debris covered the Steele glacier, which is a kilometre and a half wide. It also carried up a 300-metre ridge at the far side of the glacier, and spilled down another 700 metres onto the neighbouring Hodgson Glacier.

'It was an absolutely massive amount of rock that fell,' Lipovsky said.

The north face of Mount Steele is extremely steep and blanketed in a layer of ice called an icefall. Lipovsky estimated the icefall clinging to the north face was between 30 and 40 metres thick, and although ice formed the majority of material, there were no ice chunks found in the debris at the bottom of the slide, most likely because it was pulverized by the impact.

She added it is definitely one of the largest slides in the Yukon's recorded history, and potentially the largest ever, although it is too early to determine at this point in time.

A research team from the University of British Columbia, headed by Garry Clarke, was studying glacier dynamics at the time on Trapridge Glacier, approximately 15 kilometres north of Mount Steele.

'They were able to see the original slide on July 22, and I guess they were wondering if they should run for cover, in case the same thing happened where they were,' Lipovsky said.

The research team returned the next day to take pictures, and were still in the region when the major slide occurred. Clarke contacted Lance Goodwin at the Arctic Institute, located at Southern Kluane Lake, who in turn notified Lipovsky.

Studies have now begun to try and determine what caused the slide. Lipovsky said the slide could've been caused by a number of factors, including permafrost degradation, if the bedrock underneath had become weakened by frost shatter, or if it was seismically triggered.

'It could be one thing that was the main cause, or it could be a combination of things. Climate change could be a factor, but we can't be very conclusive about that either,' she said.

The slide has generated a huge amount of interest from top geologists across the country, including Stephen Evans from the University of Waterloo and John Clague from Simon Fraser University, who Lipovsky referred to as two of the biggest names in geohazard studies.

'This slide is really exciting for a number of reasons,' Evans said in a phone interview this morning. 'Firstly, we're always interested in landslides involving glaciers or glacial ice because they move so fast, and because they've caused fairly substantial disasters worldwide. The other reason is because we're trying to find a link between it and climate change.'

Evans conducts research on catastrophic landslides. Any landslides which travel at speeds in excess of five metres per second are deemed catastrophic landslides.

Slides of this magnitude don't happen too frequently. Evans estimated that one of this size takes place once every five years in Canada.

'Thanks to glacier melt due to global warming, mountain areas have become more susceptible to changes and stress,' Evans said. 'This is a worldwide phenomenon taking place.'

Evans is departing tonight for southern Russia, where he will study a similar slide which took place in the Caucasus Mountains in 2002. That slide, known as the Kolka event, saw a glacial debris flow which travelled 17 kilometres at an average speed of 50 metres per second.

'These are incredible velocities which are suggestive of a low friction mechanism that propels earth materials (in the presence of glaciers or glacial ice) to Formula One velocities,' Evans added.

For example, the fastest lap at the 2007 Hungarian Grand Prix, a Formula One event, was 51 metres per second.

From the data Evans has seen pertaining to the Mount Steele slide, the 300-metre run-up at the base of the initial slide, and its descent to Hodgson Glacier, indicates a minimum velocity of 70 metres per second (252 kilometres per hour).

Although Evans will be in Russia until early September, his graduate student, Keith Delaney, will be coming to the Yukon either next week or the following week in order to study the slide.

'When he goes depends on a number of factors, such as windows of opportunity due to weather and such, but I'm sure he would go tomorrow if he had the chance,' Evans said.

It will be a joint university investigation with Clague from SFU, who is currently in Cairns, Australia. The two professors have collaborated many times in the past.

Through studying slides such as the one at Mount Steele, they hope to examine and document the causes, as well as the mechanism and behaviour of such events, with the hope of developing predictive models.

'From looking at pictures of the scar, I don't think it's the safest place,' Evans said. 'There's probably more to come. I wouldn't be surprised if there's a further slide by the end of summer, a slide of equal or greater magnitude. That's my hunch.'

He pointed to recent studies which indicate that 95 per cent of recent rock avalanches in Canada are near glaciers which are becoming unstable due to loss of glacier ice.

Only one climbing party tackled Mount Steele during the 2007 climbing season, which takes place between April and end of June.

'It's a concern, although most mountaineers in the area would not be on the north face,' Lipovsky said. 'They'd be on a nearby ridge, and they'd probably be fine. But it's definitely a concern, especially if there's a potential that slides like these are going to happen more frequently.'

Kevin McLaughlin from the park wardens office at Kluane National Park and Reserve said there were 30 registered climbing parties in 2007, totalling 105 people. In 2006, there were 29 teams that climbed mountains in the region, totalling 77 people. Mount Logan is the most popular of all the peaks in the area, although parties also tackled Mount Kennedy, Mount Saskatchewan, and Pinnacle Peak.