Have you ever been inside a cave? When most people think of caves, they imagine tunnels carved through solid rock. In many places, caves are made of limestone. Where I come from, we have caves formed from lava rock due to the many volcanoes. But today, I want to tell you about a different kind of cave—one made entirely of ice! These ice caves are found in the glaciers on Mount Hood, the tallest mountain in Oregon.
Mount Hood is just an hour’s drive from Portland, Oregon’s largest city. For a cave explorer, the most thrilling experience is discovering a new cave and being the first to explore it. It’s like being an astronaut, seeing places no one has ever seen before. Imagine our excitement when we found three new caves near Portland that had never been explored or mapped!
Glaciers are like slow-moving rivers of ice. They form when snow piles up over many years, compressing into hard, blue ice. On Mount Hood, where it snows over twenty feet each year, this ice eventually starts sliding down the mountain, creating a glacier. The glacier where we found the caves is called the Sandy Glacier.
In summer, the snow on the glacier melts, forming streams that carve tunnels through the ice. These tunnels create a network of caves that change every year. Warm water and air melt the ice, making the caves taller and larger. The entire glacier, including the caves, moves slowly down the mountain.
In 2011, my exploration partner Brent McGregor and I set out to find these caves. We discovered a large crack in the ice, built anchors, and rappelled down into a massive tunnel beneath the glacier. We mapped the cave using lasers, compasses, and inclinometers, which help measure distances and angles. This math, which I once disliked, became incredibly useful!
Mapping a cave is different from mapping roads or trails. It involves creating a three-dimensional map that shows both a bird’s eye view and a side view, like an ant farm. We named our first cave Snow Dragon Cave because it felt like a dragon sleeping under the snow.
As more snow melted, we found more caves connected to Snow Dragon. One of these caves, which we named Pure Imagination, was filled with glowing blue and green ice. It was colder than Snow Dragon because cold air flowed down a shaft from the glacier’s surface, freezing everything inside.
Not much lives in these icy caves, but there are some fascinating things. Unusual bacteria live in the water, eating rock to survive. Scientists are studying these extremophiles, hoping to find similar life forms on Mars. As glaciers move, they also preserve seeds and feathers, which eventually fall into the caves. We found a seed over a hundred years old and a duck feather deep inside Snow Dragon Cave.
It’s amazing to think that these discoveries were right in our backyard. In today’s busy world, it might seem like there’s nothing left to discover, but that’s not true. New caves are found every year, and you could be the next discoverer. All it takes is curiosity and a willingness to explore places others haven’t. Who knows what you might find in your own backyard?
Thank you for joining me on this adventure!
Using clay and ice, create a model of a glacier to understand how glaciers form and move. Observe how the ice slides over the clay, simulating the glacier’s movement down a mountain. Discuss how this movement can create caves within the glacier.
Draw a map of an imaginary cave system. Include both a bird’s eye view and a side view, similar to how Eddy Cartaya mapped the glacier caves. Use your imagination to add features like tunnels, chambers, and streams.
Choose a glacier cave from another part of the world and research its unique features. Present your findings to the class, highlighting how it compares to the caves on Mount Hood.
Conduct an experiment to see how different temperatures affect ice melting. Use ice cubes and place them in different environments (e.g., warm water, cold air) to observe how they melt. Relate this to how glacier caves form and change over time.
Imagine you are an explorer discovering a new glacier cave. Write a short story about your adventure, describing the sights, sounds, and feelings you experience. Share your story with the class to inspire others to explore.
Sure! Here’s a sanitized version of the transcript:
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So how many of you have ever been in a cave before? Okay, a few of you. When you think of a cave, most of you think of a tunnel going through solid rock. In fact, that’s how most caves are. In this part of the country, many caves are made of limestone. Back where I’m from, most of our caves are made from lava rock because we have a lot of volcanoes there. But the caves I want to share with you today are made completely of ice, specifically glacier ice, formed on the side of the tallest mountain in the state of Oregon called Mount Hood.
Now, Mount Hood is only one hour’s drive from Portland, the largest city in Oregon, where over two million people live. The most exciting thing for a cave explorer is to find a new cave and be the first human to ever go into it. The second most exciting thing is to be the first one to make a map of a cave. These days, with so many people hiking around, it’s pretty hard to find a new cave, so you can imagine how excited we were to find three new caves within sight of Oregon’s largest city and realize that they had never been explored or mapped before. It was kind of like being an astronaut because we were getting to see things and go places that no one had ever seen or gone before.
So, what is a glacier? Well, those of you who have ever seen or touched snow know that it’s really light because it’s just a bunch of tiny ice crystals clumped together, and it’s mostly air. If you squish a handful of snow to make a snowball, it gets really small, hard, and dense. In a mountain like Hood, where it snows over twenty feet a year, it crushes the air out of it and gradually forms hard, blue ice. Each year, more and more ice stacks up on top of it, and eventually, it gets so heavy that it starts to slide down the mountain under its own weight, forming a slow-moving river of ice. When an ice pack like that starts to move, we call it a glacier and give it a name. The name of the glacier where these caves were formed is the Sandy Glacier.
Each year, as new snow lands on the glacier, it melts in the summer sun, forming little rivers of water that flow along the ice and start to melt and bore their way down through the glacier, forming big networks of caves, sometimes going all the way down to the underlying bedrock. The interesting thing about glacier caves is that each year, new tunnels form, and different waterfalls pop up or move around from place to place inside the cave. Warm water from the top of the ice is boring its way down, and warm air from below the mountain actually rises up, gets into the cave, and melts the ceilings back taller and taller.
But the unique aspect of glacier caves is that the entire cave is moving because it’s formed inside a block of ice the size of a small city that’s slowly sliding down the mountain. This is Brent McGregor, my cave exploration partner. He and I have both been exploring caves and climbing mountains for a long time, but neither of us had ever really explored a glacier cave before. Back in 2011, Brent saw a video of a couple of hikers who stumbled across the entrance to one of these caves. There were no GPS coordinates for it, and all we knew was that it was somewhere on the Sandy Glacier.
So, in July of that year, we went out on the glacier and found a big crack in the ice. We had to build snow and ice anchors so we could tie off ropes and rappel down into the hole. At the end of this hole, we found a huge tunnel going right up the mountain underneath thousands of tons of glacier ice. We followed this cave back for about a half mile until it came to an end. With the help of our survey tools, we made a three-dimensional map of the cave on our way back out.
So, how do you map a cave? Cave maps aren’t like trail maps or road maps because they have pits and holes going to overlapping levels. To make a cave map, you have to set up survey stations every few feet inside the cave, using a laser to measure the distance between those stations. You also use a compass and an inclinometer to measure the direction the cave is headed and the slope of the floor and ceilings. Those of you taking trigonometry will find that particular type of math very useful for making maps like this because it allows you to measure heights and distances without actually having to go there.
In fact, the more I mapped and studied caves, the more useful I found all that math that I originally disliked in school to be. When you’re done surveying, you take all this data, input it into the computer, and find someone who can draw really well to draft up a map that looks something like this. It will show you both a bird’s eye view of the passage as well as a profile view of the passage, kind of like an ant farm view. We named this cave Snow Dragon Cave because it was like a big dragon sleeping under the snow.
Later that summer, as more snow melted off the glacier, we found more caves and realized they were all connected. Not long after we mapped Snow Dragon, Brent discovered another new cave not very far away. The inside of it was coated with ice, so we had to wear spikes on our feet called crampons to walk around without slipping. This cave was amazing! The ice in the ceiling was glowing blue and green because sunlight from far above was shining through the ice and lighting it all up.
We couldn’t understand why this cave was so much colder than Snow Dragon until we got to the end and found out why. There was a huge pit or shaft called a moul that went 130 feet straight up to the surface of the glacier. Cold air from the top of the mountain was flowing down this hole, blasting through the cave and freezing everything inside of it. We were so excited about finding this new pit that we actually came back in January the following year to be the first ones to explore it. It was so cold outside that we had to sleep inside the cave.
The next morning, we climbed out of the cave and hiked all the way to the top of the glacier, where we finally rigged and rappelled down this pit for the very first time. Brent named this cave Pure Imagination because the beautiful sights we saw in there were beyond what we could have ever imagined.
So, besides the fascinating ice, what else is inside these caves? Not too much lives in them because they’re so cold, and the entrance is actually covered with snow for about eight months of the year, but there are some interesting things in there. There are unusual bacteria living in the water that actually eat and digest rock to make their own food to survive under this ice. In fact, this past summer, scientists collected samples of water and ice specifically to see if extremophiles, tiny life forms that have evolved to live in completely hostile conditions, might be living under the ice, similar to what they hope to find in the polar ice caps of Mars someday.
Another interesting aspect is that as seeds and birds land on the surface of the glacier and die, they get buried in the snow and gradually become part of the glacier, sinking deeper and deeper into the ice. As these caves form and melt their way up into the ice, they make these artifacts rain down from the ceiling and fall onto the cave floor, where we end up finding them. For example, this is a seed we found that has been frozen in ice for over a hundred years and is just now starting to sprout. This mallard duck feather was found over 1800 feet in the back of Snow Dragon Cave. This duck died on the surface of the glacier long ago, and its feathers have finally made it down through over a hundred feet of ice before falling inside the cave.
Even now, Brent and I find it hard to believe that all these discoveries were essentially in our own backyard, hidden away just waiting to be found. As I mentioned earlier, the idea of discovery in this busy world we live in seems like something you can only do with space travel now, but that’s not true. Every year, new caves get discovered that no one has ever been in before. So, it’s actually not too late for one of you to become a discoverer yourself. You just have to be willing to look, go where people don’t often go, and focus your eyes and your mind to recognize the discovery when you see it because it might be in your own backyard. Thank you very much.
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This version maintains the core content while ensuring clarity and appropriateness.
Cave – A natural underground space, typically formed by the erosion of rock, that can be large enough for a human to enter. – Scientists explored the cave to study the unique rock formations and the ecosystem within.
Glacier – A large, slow-moving mass of ice formed from compacted layers of snow, found in polar regions and high mountains. – The glacier slowly carved out the valley over thousands of years.
Ice – Frozen water, a solid state of H2O, often found in polar regions and during winter months. – The ice on the lake was thick enough for the researchers to walk on safely.
Mount Hood – A dormant stratovolcano located in Oregon, known for its snow-capped peak and popular for skiing and hiking. – The students learned about the geological history of Mount Hood during their geography class.
Snow – Precipitation in the form of ice crystals, forming a white layer on the ground in cold weather. – The heavy snow covered the mountain, creating perfect conditions for the scientific study of alpine ecosystems.
Bacteria – Microscopic single-celled organisms that can be found in various environments, some of which are beneficial while others can cause disease. – The scientists discovered a new type of bacteria living in the hot springs near the volcano.
Exploration – The act of traveling through an unfamiliar area to learn about it, often involving scientific research and discovery. – The exploration of the rainforest led to the discovery of several new plant species.
Discovery – The act of finding or learning something for the first time, often leading to new knowledge or understanding. – The discovery of fossils in the desert provided new insights into ancient life on Earth.
Tunnels – Underground passages, often created by humans or natural processes, used for transportation or exploration. – The team used the tunnels beneath the city to study the effects of urban development on groundwater flow.
Oregon – A state in the Pacific Northwest region of the United States, known for its diverse landscapes including forests, mountains, and coastline. – The geography class took a field trip to Oregon to study its volcanic features and coastal ecosystems.
