Perito Moreno Glacier observation decks (Patagonia)

We visited the Perito Moreno Glacier observation decks twice over two days.

Our first visit was in the afternoon of our Perito Moreno Glacier mini trekking tour and our second was the following day as a do-it-yourself visit to Parque Nacional Los Glaciares, home of the glacier.

Day 1 observation decks

After our mini trekking tour, we were given two hours to explore the park.

It was not enough time to spend in the park, so if you are doing a do-it-yourself visit to the park, plan for at least four hours and bring a picnic lunch.

The glacier is mesmerizing; you won’t want to leave once you are there. 

I call this gallery “Layers.”

During our visit, the temperature was in the mid-60s, and the guides told us that we were “lucky” for the seasonally warm temperatures because the glacier would be active. 

Watching a glacier is a lot like being on safari. Ninety-eight percent of the time is spent waiting for something to happen. Anything to happen. The other two percent is when that something happens.

The first big glacier event occurred earlier in the day on our walk to the storage hut on our mini trekking tour. We heard a big boom and turned around to see the glacier calving.

It sounded like lightning and thunder.

The crackling and booming caught me off guard because I could not pinpoint where the noise was coming from. 

We heard countless “false booms” from deep in the glacier.

Heads would turn with every boom. Even with the deep booms coming from far back in the glacier, we could hear chunks splash into the water and wonder where those chunks were because there was no visible splashing or water movement in view. 

Every once in a while, the glacier would experience calving on its face.

Note: The audio has been removed from the video below due to my ‘colorful’ commentary about the tree being in the line of sight.

Being in the right spot at the right time comes down to luck.

We’d been watching the area in the video above for about an hour when it finally crashed into the lake. There’d been several mini booms leading up to the big boom, and we felt something was about to happen. We stuck around, patiently waiting, and were rewarded.

The park has three main observation decks, not including the main deck at the top. We spent most of the two hours on the lower observation deck because that was the area experiencing the most booms. 

Below is a photo taken from the top deck with the lower “booming” deck in view.

The two calving events, first on our mini trekking tour and then on the lower deck, were the only two notable events of our first day at the park.

For some, this may have been enough, but not for us. We had been bitten by the Perito Moreno Glacier bug and needed to see more and decided to return the following day.

Day 2 observation decks

The weather on our second visit was opposite from our first day. It was cold and cloudy, so the glacier would be less active (good for the glacier, bad for entertainment).

I spent a lot of time reading the informational signs on the observation decks. The text was translated into English, but many acronyms made it difficult to understand.

Being somewhat bored and inherently curious, I took a photo of the signs on the decks, and Google Translated the text later that night.

Fun facts

From the observation decks, the ablation zone of Perito Moreno is in view. Ablation is the opposite of accumulation. 

In short, visitors look at the glacier area losing mass due to melting, evaporation, calving, etc. 

Perito Moreno has an area of 98 square miles (254 square kilometers). For comparison’s sake, Washington DC is 68 square miles (176 sq km).

Perito Moreno varies in altitude from 9,842 feet (1.76 miles or 3,000 meters) above sea level to 607 feet (185 meters) above sea level at its terminus.

Perito Moreno is 14.6 miles (23.5 km) long from Cerro Pietrobelli (ice divide with Chile) and 19 miles (31 km) long from Glacier Frias.

Perito Moreno is 3 miles (4.8 km) wide. 

Though the glacier did appear wide, it was hard to believe that its width was three miles. I suppose anything is possible – it’s hard to understand the scale of the glacier, even when standing in front of it.

The surface of Perito Moreno is shaped by the wind. It’s a bunch of tall ice columns packed together. Some columns lean to the left, others lean to the right, like wind-swept hair.

Seismic shooting has revealed that the ice thickness at the centreline of the glacier is 2,296 feet (.43 miles or 700 meters). There is an ice thickness of 26 ft (8 meters) upstream. 

Upstream, the surface ice velocity is more than 6.56 feet (2 meters) per day.

Day 2 observation decks continued

We were at the glacier for a couple of hours when we started to hear some mini booms and felt like something was about to happen. Ironically yet expected, this was also the time when we were about to set off for a toilet break.

That’s the thing with glacier watching. The moment you turn your back, something happens. The fear of missing out is always with you while at the glacier.

A few moments later, a huge slab crashed into the water.

The crowd went wild!

Ooooohhhh, aaaaahhhh!

It was a grand display!

I was somewhat prepared for this event, but the crashes are incredibly fast for something that has taken five centuries to get where it was. 

And just like that, the excitement was over.

We hung around for 10 or 15 more minutes, hoping there would be aftershocks and more calving, but things went calm and remained that way for the rest of our visit.

We spent six hours on the observation decks at Parque Nacional Los Glaciares. Two hours were spent on our first day when most of the action happened, and we spent an additional four hours on our second day.

What we’d do differently

There isn’t anything we’d do differently regarding Perito Moreno Glacier; however, the mini trekking tour was not as cool as I anticipated. It also felt wrong to be trekking on the glacier.

If we were to do the trip over again, we’d possibly skip the mini trekking tour and do two do-it-yourself park visits.

The next post on Argentina is here.