A month-long expedition to Antarctica has brought scientists and researchers to the widest glacier on Earth, the Thwaites Glacier.

It's also nicknamed the Doomsday Glacier because of its potential impact to raise sea levels if ice continues to melt.

Our science correspondent, Miles O'Brien, is on that trip.

The primary challenge for many of the researchers, they're trying to drill

a small hole on the glacier at the place where ice, land, and the sea meet some 3,000 feet below,

the so-called grounding line. The instruments they drop into the seawater could yield unprecedented

data. Miles has been visiting the base camp today and has this look at the challenges of what

they're doing, part of our recurring series, Tipping Point. So how do you drill a hot water

hole into a glacier 3,000 feet? Well, the first thing you need is a lot of hot water. And fortunately, there's a pretty much never-ending source of snow here. Behind me, these are called flubbers. The team here, there are 10 people here, had to shovel over the course of the past week or so, 20 tons of snow into those containers. They are truly practicing oceanography the hard way.

It's hard work, the weather was terrible, but they got what they needed to do this hot water drill hole.

Let's take a look at what else is going on here. Okay, so shoveling 20 tons of snow is just for starters.

You got to melt it.

So those three boxes over there, those are generators.

They're connected to those three boxes with heaters.

There's two, four, six of them. That turns the snow into water at

194 degrees Fahrenheit. It gets sent through this black hose. This is the key drilling

hose on that black spool, and it goes down the hole. There are two other spools there that

are very important. The orange spool, which they're using right now, is how you drop down the instruments that don't need to communicate with the surface, things like cameras and so forth. The silver spool right there, that's coaxial cable. It can carry data. So if you have an instrument where you want to keep reading the data as it goes down, you use that.

Hard to believe 3,000 feet below where I stand. We're actually floating on the Amazon Sea.

But this is how you get all the scientific instruments, get the data that scientists are so interested in finding

about why this glacier is melting so quickly.

This is the science tent. This is the stuff that's going down the hole.

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