In his quest for a bottle of fine scotch, takes on the Perito Moreno Glacier and witnesses the spectacular collapse of its advancing face.

Neil Ratley

The crack and rumble of rifle fire reverberates through the jags of cobalt blue ice. I freeze for a moment and my crampons claw and gnash into the slippery surface beneath me.

I am perched on Perito Moreno Glacier whose ancient frozen bulk slides into Lago Argentino at the southern tip of the Southern Patagonian Ice Field.

The 250 square kilometre ice formation is 30 kilometres long and is one of 48 glaciers fed by the ice field in the Andes mountain range dividing Argentina and Chile. It is the world’s third largest reserve of fresh water.

The echo falls away and a chunk of ice the size of a two-storey building crashes into the lake.

For a moment I question why I am taking a morning stroll across an advancing glacier.

Oh that’s right, I hear a rumour there is a bottle of fine scotch waiting somewhere out there on the ice. I may need the whole bottle if slabs as big as houses keep shearing off.

A few days earlier, wind swept and wind burnt, I rode into El Calafate from the desolate and ceaseless Patagonian Steppe. The town is the gateway to Los Glaciares National Park, home to Argentina’s massive Perito Moreno Glacier.

El Calafate, normally buzzing and bustling with touts for glacier tours, is a ghost town. The one poor soul manning the tourist information office lets me know why. I have timed my arrival to coincide with one of nature’s most impressive shows.

The day before my ice trek I find myself standing slack-jawed and frosty with a throng of Argentinians and foreigners as Perito Moreno Glacier undergoes its rare rupture – a spectacular collapse of its advancing face.

The solid mass of blue ice is aweinspiring. It has a 5km frontage about 60 metres in height dropping vertically into the water of Lago Argentino. Over time, the glacier creeps across the lake to the shore and about every four years eventually cuts the southern arm known as the Brazo Rico off from the rest of the lake. The mounting water pressure builds in ice-melt fed Brazo Rico and bores a small hole in the ice wall. This small leak ultimately is the catalyst for a spectacular demolition show.

After the first crack appears in the frozen dam wall, it is only a matter of time before the wall falls. The water flowing through from the Brazo Rico widens the crack. It relentlessly nibbles away then gnaws chunks out of the glacier’s snout. An ice bridge forms as the water funnels through. Moment by moment the hard fought ground won by Perito Moreno is lost to the force of the water and the tunnel grows wider weakening the bridge.

Under a brooding sky icy droplets of rain spittle, the hiss of anticipation escapes in foggy clouds from the open mouths of the masses lining the walkways and viewpoints opposite the imploding glacier.

From my vantage point I can see the water pouring through the growing span of the bridge. Frozen chunks swirl In slow motion, pieces of ice the size of buses come crashing down. They are swallowed by the water, which after a few moments belches up gushing waves. and twirl in the washpool. Ice continues to drop like shards of glass. A shower of smaller pieces turns into a cascade of giant blocks. In slow motion, pieces of ice the size of buses come crashing down. They are swallowed by the water, which after a few moments belches up gushing waves.

Each time Perito Moreno sheds a layer of ice, the crowd anticipates the cataclysmic end.