Geology of the National Parks



There are three Unit 3 GeoClips (movies) linked below. We hope they help you understand Unit 3 just a little bit better, and that you enjoy them.

Hawaii: Night Lava

Hawaii Night Lava
Click Here for Transcript of Hawaii: Night Lava Video

Hawaii Volcanoes National Park below the east rift Kilauea, this is the lava headed for the sea. It is 2,000 degrees Fahrenheit or so. This is the innards of the Earth turning inside out, building new land that we're sitting on right now. And this is way cool because it's so hot. You just can't imagine what this is like.

Below us, it is fountaining into the sea and jetting up great bursts of steam. New land being born, this is geology in action, this is the real thing. The breeze blowing over us is a little bit sulfurous, it's a little bit warm-- we're going to get out of here fairly quickly. But we're having a lot of fun, I wish you could be here with us. This is an amazing, amazing sight.

Credit: Dr. Richard Alley

Hawaii: Lava Tube

Hawaii: Lava Tube
Click Here for Transcript of Hawaii: Lava Tube Video

We're in the rain forest on the side of Kilauea, and behind me is a lava tube. A great lava flow came through here in the past, the top freezes first, the sides freeze, the inside-- glowing hot lava-- comes flowing out, and it drains. And you go inside and there'll be stalactites that were little drips that were falling off the ceiling when they froze. And this is the way a lot of the lava gets to the coast. It's that the top will freeze and the insides will go squirting on out to the sea. And so it's a really interesting place, a very different kind of cave.

Credit: Dr. Richard Alley

The hot spot of Hawaii erupts runny lava to the surface, giving some very interesting features, such as the lava tubes you will see forming in the first video, and formed in the second video. The hike out to the flowing lava was, in spring of 2007, over three miles across rough, often broken and glassy lava that solidified from glowing hot flows over the last couple of decades. Whales were spouting offshore when Dr. Alley and family made the trip. Tag along, and see what they saw.

Hawaii: Southwest Rift

Hawaii: Southwest Rift
Click Here for Transcript of Hawaii: Southwest Rift Video

The Southwest Rift of Kilauea on Hawaii. There's a vast and fascinating volcanic history sitting here. Layers of rock that were made of pieces that were tossed through the air. Glass that froze in the air as it was thrown as molten little bits from the volcano, and then other sorts of layers.

Then there's been a great cracking here, probably an inflation from underneath as melted rock is moving underneath that sort of bubbles things up and breaks it. Then an eruption happened at some point, and there was actually sort of a waterfall of melted rock, and it was flowing into the crack. And we can see behind me all these places where this stuff has flown down into the crack. Just a wonderful record of the excitement of the geology of this place.

Credit: Dr. Richard Alley

Lava was erupting in the Southwest Rift of Kilauea not that long ago. Sometimes, the lava erupts with a little force, throwing pieces that freeze to glass in the air and rain down. Other times, the lava flows even more quietly along the surface. Here, you can see evidence of both.

Want to see more?

Optional Videos, for your enjoyment (and education, but you won't be quizzed on them.) Volcanoes are just too interesting to leave so quickly, so here are some more looks at these important, and dangerous, pieces of our planet. First, visit Hawaii again, and see some strange things. Then, head over to Sunset Crater Volcano National Monument, Arizona, with the CAUSE class. Have fun, and keep your feet cool!

Hawaii: Tree Mold

Hawaii: Tree Mold
Click Here for Transcript of Hawaii: Tree Mold Video

I am in one of the stranger positions in one of the stranger places you'll ever see. The camera is looking right down on me, and I am sort of lying over the ground. And behind my head is a tree mold in Hawaii Volcanoes National Park. There used to be a giant Ohia tree here. A lava flow came in around it, the lava chilled where it hit that tree and was boiling the water away from the bark. Eventually the tree rotted out, but it left its shell of lava sitting here behind me, and you can see sort of the shape of the bark sitting here in the tree.

Then a new tree has grown, and is putting its roots down in the hole where the old one was. But this is the mold that was left from a tree that was hit by a lava flow. And it's really something you can see. There's places in the park where there are footprints that you can see, where people walked in the lava, and here's the mark of a tree.

Credit: Dr. Richard Alley

Hawaiian lava flows engulf whatever is in their way, including trees. What happens when hot lava hits a cold, wet tree? Find out here, your chance to look down on Dr. Alley.

Hawaii: Boiling Cauldrons

Hawaii: Boiling Cauldrons
Click Here for Transcript of Hawaii: Boiling Cauldrons Video

Kilauea, Hawaii Volcanoes National Park. Deep beneath us a boiling cauldron of melted rock that wells up from possibly the core mantel boundary on the giant hot spot that is Hawaii. Next to us, the great crater here, fills with magma, with lava, that comes boiling up from below. And then it rifts out, it breaks, and you get cracks in the ground, and the lava flows out, and it is now flowing into the sea and building new pieces of the island just below us down at the coast.

Around me here, you can see swirling-- the fogs, the mists, the steam, the hot sulfurous gases that come off of this volcano. Where the rain from above soaks down through the cracks, it hits a hot rock, it flashes to steam, and it comes boiling out. This is a place where geology lives, where geology is living right now. And it's an amazing place to try to breathe in this.

Credit: Dr. Richard Alley

Kilauea Volcano is a wonderful place to visit. Stay in the lodge on the rim, and you'll wake up to the view shown here behind Dr. Alley.

Cinder cones are rather odd volcanoes, formed of pyroclastic bits tossed through the air to pile up near the vent. If you let the spaghetti sauce boil on the stove, without a lid, you would soon have a lot of tomato-sauce blobs around the pot. Let those build up, and you are heading for a cinder cone. Here, see three different versions of the cinder cones at Sunset Crater.

CAUSE 2004 - Sunset National Park #1

Sunset National Park #1
Click Here for Transcript of Sunset National Park #1

Right now we're at-- this is called Lenox Crater, and it's a volcano. It's a cinder cone volcano. If you looked around behind us, right at the center there's a big crater, hence the name. And all the stuff that we're sitting on right here is cinders, basalt rock that was ejected from the volcano. And as it was ejected, it was thrown up and out, kind of like this. And--

Kind of like what?


Kind of like that. And it just over the years built up and built this-- what did it say, it's 400 feet high or something like that? Yeah. Not too bad.

Credit: Dr. Richard Alley

An explanation of cinder cone volcano formation by CAUSE student Sam A.

CAUSE 2004 - Sunset National Park #2

Sunset National Park #2
Click Here for Transcript of Sunset National Park #2

ROh. That was hard. Why?

Well, Ryan you just walked up a really steep side of a volcano.

What volcano?

This volcano.

That's a volcano?

Yeah. Right over there's the center of the volcano. And we're sitting on top of cinders that were thrown out of the volcano.

What's a cinder?

These are cinders.

What are they?

OK, imagine this is the bottom of the volcano. Stuff's thrown out of the center of the volcano. And it starts to build up around the side. So eventually when enough stuff's thrown out, you get a steep-sided volcano. It's just layer, upon layer, upon layer, upon layer, upon layer of stuff that's ejected out of the volcano, falling down on top of each other.

How far does cinder travel?

Well, we're sitting about a quarter mile from the center of the volcano, so these cinders traveled about a quarter mile. They can go further than that, a mile.

So if this is cinder, it's so small. I mean, are they all this small?

Yeah. Well, some are real small, some are a little small. Some are big, and some are the size of Volkswagens.

Oh. But Stef, I still don't get it. I mean, where else are we going to see this in the real world?

Have you ever made spaghetti?


All right. Well, think of a pot of spaghetti sauce. You've got the heat cranked up real high, and the sauce starts boiling. You get bubbles and then, next thing you know, you've got butter and spaghetti sauce. You've got spatters of sauce all over your kitchen stove.

And that's exactly what's going on over here?

Yeah. Why don't we go to take a look?


Go down in the crater.


Credit: Dr. Richard Alley

Another, slightly "dramatized" explanation of cinder cone volcano formation by CAUSE students Stephanie S. and Raya G.

CAUSE 2004 - Sunset National Park #3

Sunset National Park #3
Click Here for Transcript of Sunset National Park #3

We're looking at Sunset Crater, a volcano that erupted almost 1,000 years ago. It's primarily a cinder cone, so when it was erupting it was sort of spitting out little pieces like a pot of spaghetti sauce bubbling and throwing things.

Those little pieces-- we can actually see similar pieces from either that one or a different eruption here. And we've been walking on them, and they're not terribly pleasant for walking on, but you can build a pile out of stuff like this. There's probably lava flows helping to hold that one up.

A little more oxidized late in the eruption and so you get that pretty red around the top that gives the Sunset Crater name.

Credit: Dr. Richard Alley

A third explanation of cinder cone volcano formation, by Dr. Alley himself.