Ejecting fire, molten rock, giant boulders and poisonous gases, the volcano can be a hazard for researchers, homeowners, plants and animals, but it doesn’t just leave destruction in its wake. Twists and turns in the lava’s flow leave some patches of original ecosystems, called kipukas, undisturbed. These oases of life provide a haven to many rare creatures — including the Hawaiian state bird, the Nene — but remain in constant danger from the volcano and from invasive species. Below the surface, inactive lava tubes provide homes for many unique species of darkness-loving creatures called troglobites.

At the end of its journey, the lava meets the ocean. Braving an extremely hot sea, filmmakers record the birth of new land and the incredible phenomenon of pillow lava – a bizarre and truly magical sight to behold.

Violent and beautiful, destructive and creative, Kilauea: Mountain of Fire explores the incredible power of the volcano and the challenges of life in its shadow.

Kilauea: Mountain of Fire premieres Sunday, March 29 on PBS.

The Drakensberg mountain range extends more than 600 miles across Southern Africa.  It encompasses massive sandstone buttresses, grass-covered plateaus, and cathedral-like rock towers that have earned these mountains their Zulu name, uKhahlamba, “barrier of spears.”  In its alpine pastures, dangerous thunderstorms can gather in a matter of moments. Not far away, the Tugela Falls plummets more than 3,100 feet into a sparkling rainbow of water vapor. The mountains’ treachery is paired with stunning natural beauty. But how exactly did these extraordinary mountains get here?

The story begins about three billion years ago, when this landmass was part of a supercontinent known as Gondwanaland. At that time, scientists believe a massive lake covered the granite foundation on which the mountains now stand.  Over the course of millions of years, runoff carried sand and mud into the lake, where it settled into sedimentary layers that hardened under the compacting weight. This process carried on until several hundred million years ago.  The youngest of these sedimentary layers now lies exposed in the cliffs at the base of the Drakensberg range.

Tugela Falls, seen through a rock cleft

Then, around 160 million years ago, immense pressure deep within the Earth caused Gondwanaland to begin to split apart. The slowly drifting tectonic plates would eventually form the continents of today.  In this period of great change, vast lava flows poured out through fractures in the Earth’s crust.  Sometimes, these flows hardened into layers of basalt more than 150 feet deep. Over about 20 million years, the basalt deposits grew to be nearly a mile thick over the sandstone deposits below.

When the lava flows stopped, some 140 million years ago,  the process of building this extraordinary mountain range was halted — and a slow process of wearing away began. Along the escarpment, erosion often follows fracture planes that form deep within the rock. As the rocks crumble along these planes, broad cliff faces form — sometimes extending in a straight line for many miles.   Higher still, the layers of hard basalt have long since been whittled down by time and the elements. Blocks and slabs were shorn away, then pulverized over centuries of weathering or were swallowed by the Drakensberg’s deep ravines.  Now, only towering basalt peaks remain, a chain of sentinels keeping watch over the landscape.  The debris from this long process has been churned into a black soil that supports the grasses that cover the slopes below.

With its incredible geologic history, breathtaking landscapes, and wealth of San rock art, the uKhahlamba Drakensberg Park was named a World Heritage site by the United Nations Educational Scientific and Cultural Organization in 2000.  The range now plays host to tourists who travel here to enjoy the unique vistas, rugged trails, and challenging rock climbing the Drakensberg affords.  From every vantage point, the “dragon mountains” bear the evidence of the powerful forces that have shaped them through the ages.

Photos © AWF

It is one of Death Valley’s most intriguing geological whodunits — the sliding rocks of the Racetrack Playa.

On an ancient lakebed located on the western side of Death Valley National Park, boulders that weigh up to 700 pounds sail across the almost perfectly flat terrain, leaving grooved trails in their wake. As NATURE’s Life in Death Valley shows, each of these furrows chronicles a rock’s journey, ranging from a mere few inches to nearly 3,000 feet. Some tracks manifest in straight bold lines, while others coil back on themselves in sinuous arcs.

Despite a century of scientific investigation, this curious phenomenon has confounded the geological community and park visitors alike. To this day, no one has ever seen the rocks move. But in lieu of eyewitnesses, countless theories have been put forward over the years in an effort to explain the reasons behind the migrations.

One early suggestion was that the rocks were driven by gravity, sliding down a gradual slope over a long period of time. But this theory was discounted when it was revealed that the northern end of the playa is actually several centimeters higher than the southern end and that most of the rocks were in fact traveling uphill.

Though no one has yet been able to conclusively identify just what makes the rocks move, one woman is coming closer to solving the mystery. For the past ten years, Dr. Paula Messina, professor of geology at San Jose State University in California, has made it her quest to understand what has bewildered geologists for decades. “It’s interesting that no one has seen them move, so I am kind of sleuthing to see what’s really going on here,” says Dr. Messina.

Many scientists had dedicated much of their careers to the racing rocks, but the remoteness of the area kept their research limited in scope. No one had been able to map the complete set of trails before the advent of a quick, portable method known as global positioning. Dr. Messina was the first to have the luxury of this high technology at her fingertips.

In 1996, armed with a hand-held GPS unit, she digitally mapped the location of each of the 162 rocks scattered over the playa. “I’m very fortunate that this technology was available at about the same time the Racetrack captured my interest,” she says. “It took only ten days to map the entire network — a total of about 60 miles.” Since then, she has continued to chart the movements of each rock within a centimeter of accuracy. Walking the length of a trail, she collects the longitude and latitude points of each, which snap into a line. She then takes her data back to the lab where she is able to analyze changes in the rocks’ positions since her last visit.

She has found that two components are essential to their movement: wind and water. The fierce winter storms that sweep down from the surrounding mountains carry plenty of both.

The playa surface is made up of very fine clay sediments that become extremely slick when wet. “When you have pliable, wet, frictionless sediments and intense winds blowing through,” offers Dr. Messina, “I think you have the elements to make the rocks move.”

At an elevation of 3,700 feet, strong winds can rake the playa at 70 miles per hour. But Dr. Messina is quick to point out that sometimes even smaller gusts can set the rocks in motion. The explanation for this lies in her theory, which links wind and water with yet another element: bacteria.

After periods of rain, bacteria lying dormant on the playa begin to “come to.” As they grow, long, hair-like filaments develop and cause a slippery film to form on the surface. “Very rough surfaces would require great forces to move the lightest-weight rocks,” she says. “But if the surface is exceptionally smooth, as would be expected from a bio-geologic film, even the heaviest rocks could be propelled by a small shove of the wind. I think of the Racetrack as being coated by Teflon, under those special conditions.”

In science, hypotheses are often based on logic. But over the years, Dr. Messina has discovered that on the Racetrack, logic itself must often be tossed to the wind. “Some of the rocks have done some very unusual things,” she says.

In her initial analysis she hypothesized that given their weight, larger rocks would travel shorter distances and smaller, lighter rocks would sail on further, producing longer trails. It also seemed reasonable that the heavier, angular rocks would leave straighter trails and rounder rocks would move more erratically.

What she discovered surprised her. “I was crunching numbers and found that there was absolutely no correlation between the size and shape of the rocks and their trails. There was no smoking gun, so this was one of the big mysteries to me.” What appears as a very flat, uniform terrain is in fact a mosaic of microclimates. In the southeastern part of the playa, wind is channeled through a low pass in the mountains, forming a natural wind tunnel. This is where the longest, straightest trails are concentrated. In the central part of the playa, two natural wind tunnels converge from different directions, creating turbulence. It’s in this area that the rock trails are the most convoluted. “What I think is happening,” proposes Dr. Messina, “is the surrounding topography is actually what is guiding the rocks and telling them where to go.”

Some people have suggested attaching radio transmitters to the rocks or erecting cameras to catch them “in the act” in order to put an end to the speculation. But as Death Valley National Park is 95 percent designated wilderness, all research in the park must be noninvasive. It is forbidden to erect any permanent structures or instrumentation. Further, no one is permitted on the playa when it is wet because each footprint would leave an indelible scar.

As for Dr. Messina, she is content in the sleuthing. “People frequently ask me if I want to see the rocks in action and I can honestly answer that I do not,” she says. “Science is all about the quest for knowledge, and not necessarily knowing all the answers. Part of the lure of this place is its mystery. It’s fine with me if it remains that way.”

Grade Level: 9-12

Time Allotment: Two to three 45-minute class periods

Overview: We don’t often think about glaciers in our everyday lives, even though their effects are all around us. Glaciers have played a large role in shaping the world around us, from the large boulders in Central Park to the rolling hills of Ireland to Minnesota’s 10,000 lakes. For hundreds of thousands of years, the movement of glaciers has shaped land through erosion and deposition, creating landforms such as U-shaped valleys, drumlins, horns and arêtes, moraines, and kettle lakes. Currently, glacial retreat is implicated in the Earth’s changing climate patterns and may have a great impact on sea levels and weather cycles.

In this lesson, students learn how glaciers and glacial movement have affected the Earth through a series of Web interactives and hands-on activities. They learn fundamental information and terminology regarding glaciers and glaciation, and will then complete an activity using model glaciers to simulate effects on the landscape. Students then use video segments and satellite images to identify the effects of glaciation in various parts of the world. Lastly, they review current theories about cycles of climate change and relate them to glaciers and ice sheets existing today.

Subject matter: Earth Science\Glaciations\Erosion

Learning Objectives:

Students will be able to:

• Define key terms pertaining to glaciers and glaciation;
• Describe the formation process of glaciers and glacial motion;
• Explain several ways in which glaciers erode the land;
• Describe features of glacial deposition and explain how they occur;
• Recognize features of glacial erosion and deposition on landscapes;
• Explain the relationship between glaciers/ice caps and climate patterns.

STANDARDS AND CURRICULUM ALIGNMENT:

National Science Education Standards

Earth and Space Science

CONTENT STANDARD D: As a result of their activities in grades 9-12, all students should develop an understanding of

• Energy in the earth system
• Geochemical cycles
• Origin and evolution of the earth system
• Origin and evolution of the universe

Students find that the geologic record suggests that the global temperature has fluctuated within a relatively narrow range, one that has been narrow enough to enable life to survive and evolve for over three billion years. They come to understand that some of the small temperature fluctuations have produced what we perceive as dramatic effects in the earth system, such as the ice ages and the extinction of entire species. They explore the regulation of earth’s global temperature by the water and carbon cycles. Using this background, students can examine environmental changes occurring today and make predictions about future temperature fluctuations in the earth system.

Interactions among the solid earth, the oceans, the atmosphere, and organisms have resulted in the ongoing evolution of the earth system. We can observe some changes such as earthquakes and volcanic eruptions on a human time scale, but many processes such as mountain building and plate movements take place over hundreds of millions of years.

NEW YORK STATE CORE CURRICULUM ALIGNMENTS

Earth Science Core Curriculum

STANDARD 1: Students will use mathematical analysis, scientific inquiry, and engineering designs, as appropriate, to pose questions, seek answers, and develop solutions.

SCIENTIFIC INQUIRY

Key Idea 1: The central purpose of scientific inquiry is to develop explanations of natural phenomena in a continuing, creative process.

STANDARD 4: Students will understand and apply scientific concepts, principles, and theories pertaining to the physical setting and earth science recognizing the historical development of ideas in science.

Key Idea 2: Many of the phenomena that we observe on Earth involve interactions among components of air, water, and land.

Performance Indicator 2.1: Use the concepts of density and heat energy to explain observations of weather patterns, seasonal changes, and the movements of Earth’s plates.

2.1r Climate variations, structure, and characteristics of bedrock influence the development of landscape features including mountains, plateaus, plains, valleys, ridges, escarpments, and stream drainage patterns.

2.1s Weathering is the physical and chemical breakdown of rocks at or near Earth’s surface. Soils are the result of weathering and biological activity over long periods of time.

2.1t Natural agents of erosion, generally driven by gravity, remove, transport, and deposit weathered rock particles. Each agent of erosion produces distinctive changes in the material that it transports and creates characteristic surface features and landscapes. In certain erosional situations, loss of property, personal injury, and loss of life can be reduced by effective emergency preparedness.

2.1u The natural agents of erosion include:

Glaciers (moving ice): Glacial erosional processes include the formation of U-shaped valleys, parallel scratches, and grooves in bedrock. Glacial features include moraines, drumlins, kettle lakes, finger lakes, and outwash plains.

Mass Movement: Earth materials move downslope under the influence of gravity.

2.1v Patterns of deposition result from a loss of energy within the transporting system and are influenced by the size, shape, and density of the transported particles. Sediment deposits may be sorted or unsorted.

MEDIA COMPONENTS

Video:

NATURE, Ireland, selected clips:

Clip 1, “Forming the Burren”

This clip describes how glaciers eroded the bedrock of Ireland’s landscape.

Clip 2, “Glaciated Landscape”

This clip shows the many different features and effects of glaciers in Ireland.

Access the streaming and downloadable video segments for this lesson at the Video Segments Page.

Web Sites:

Our Environment: Glaciers
This interactive describes valley and continental glaciers and gives an in-depth explanation of the features of the glaciers and their effects on the landscape.

Life Cycle of a Glacier
This interactive from NOVA shows how a single snowflake makes it to the bottom of a glacier.

New York Satellite Images – Satellite Photo Map
This map contains satellite image of New York State.

Milankovitch Cycles – Interactivity – MSN Encarta
This interactive explains the three periodic variations in the Earth’s orientation toward the Sun, which are believed to cause cyclical changes in climate.

Earth science reference table for Regents exam

Materials:

For each student:

• Earth Science Reference Table – page 8
• Glacier Overview Organizer (PDF) (RTF)
• Life Cycle of a Glacier Organizer (PDF) (RTF)
• Milankovitch Cycles Organizer (PDF) (RTF)
• One model glacier
• Paper plate

For each pair/group:

• Computer with Internet access
• 5 oz. play dough (homemade or purchased)

For the class:

• Computer with Internet access, projector, and screen
• TV and DVD player
• Materials for model glaciers (to be constructed by teacher)
  • Dirt/gravel mixture (approximately 1 tablespoon per student)
  • Ice cube trays (enough for each student in the class to get one cube)
  • Water (enough to fill ice cube trays)

• Organizer Answer Keys:
  • Glacier Overview Answer Key (PDF) (RTF)
  • Life Cycle of a Glacier Answer Key (PDF) (RTF)
  • Milankovitch Cycles Answer Key (PDF) (RTF)
  • Effects of Glaciers in New York State Answer Key (PDF) (RTF)

PREP FOR TEACHERS

Prior to teaching this lesson, you will need to:

Preview all of the video clips and Web sites used in the lesson.

Download the video clips used in the lesson to your classroom computer, or prepare to watch them using your classroom’s Internet connection.

Bookmark the Web sites used in the lesson on each computer in your classroom. Using a social bookmarking tool such as del.icio.us or diigo (or an online bookmarking utility such as portaportal) will allow you to organize all the links in a central location.

Make copies of Earth Science Reference Table, page 8, for each student in your class.

Make copies of all student organizers for each student in your class.

Prepare model glaciers for students by following these steps:

1. Prepare mixture of dirt and gravel. Particles should be of different sizes. You will need approximately one tablespoon of the mixture for each student in the class.
2. Add mixture to ice cube trays. Each ice cube slot should be filled about halfway with the mixture.
3. Fill trays with water.
4. Freeze overnight.

Next: Proceed to Activities

Background:
Ireland, like much of the Northern Hemisphere, was completely covered by glaciers during the Ice Age. As the glaciers advanced and retreated over the land, they shaped and changed the surface of the landmass through the processes of erosion and sedimentation. Segments from the NATURE episode “Ireland” provide examples of the effects glaciers can have on a landscape.

Suggested Focus Questions:

Clip 1: Forming the Burren

1. How did the glaciers change the limestone outcrops?
2. How did large boulders come to rest on flat stretches of land?
3. What might the Burren look like if the glaciers covering it had been larger, and had moved at a faster pace?

Clip 2: Glaciated Landscape

1. How did frost action change the rock faces?
2. Describe Ireland’s landscape during the Ice Age.
3. What features of the landscape appear to be sculpted by glaciers? How can you tell?

Downloadable QuickTime versions of the video segments:
(Note: To download a video, right=click on the video title and click “Save Link As…’ or “Save Target As…”. On a Mac, press the CTRL key and simultaneously click the mouse, then save the link.)

Clip 1, “Forming the Burren”

Clip 2, “Glaciated Landscape“

Big Sur’s rugged mountains, crashing surf, and abundant wildlife have captivated generations of visitors. But the region has also attracted scientists bent on understanding this remarkable biological melting pot, where plants and animals from dramatically different ecosystems often mingle side by side. One biologist who has taken a close look is Paul Henson, who lived in the region in the 1980s and, with Don Usner, wrote The Natural History of Big Sur (University of California Press, 1996).

Big Sur attracts scientists due to its status as a biological melting pot. In no other part of the world do fog-loving coastal redwoods thrive on one slope of a canyon while arid-climate yuccas grow on the other, the book notes. Similarly, sea otters and cormorants live near dry-climate creatures like canyon wrens and whiptail lizards.

Henson, who now works for the U.S. Fish and Wildlife Service overseeing biological studies in Hawaii and other Pacific Islands, spoke with NATURE about Big Sur’s remarkable diversity.

How did you come to write this book?

I earned my undergraduate degree at the University of California, Santa Cruz, and did a lot of work at a university reserve called Big Creek that covers a big chunk of the Big Sur coast. Then, in the mid-1980s, I got a job doing sea otter research. During my down time, we started on the natural history guide. We realized that there was lots of good information floating around, but it hadn’t been consolidated in one place, and made accessible to scientists and understandable to regular readers. So we decided to do it.

Big Sur attracts scientists due to its status as a biological melting pot.

What makes Big Sur unusual?

For lack of a better term, it represents a kind of harmonic convergence of different ecological zones. It’s where the north meets the south, for instance. What’s called the Oregonia province to the north meets the Californian province to the south. So you have redwood trees meeting cacti and intermingling. You have northern and southern species of marine alga. One minute, you are hiking along in a wet cool canyon, and all of a sudden there will be a cactus. One minute it smells like Oregon and the next it smells like Mexico.

The geology plays are role, right?

The geology and topography forms the basis for it all, and it has driven geologists crazy for years. It’s incredibly jumbled and complicated. You have all these faults and slices of rock that have moved over time. And then on top of that you have a very interesting climate. Big Sur has a Mediterranean climate, which it shares with just four or five other areas in the world. It’s a climate that is extremely conducive to a lot of plants doing well. Taken together, those things make it one of the most ecologically fascinating and diverse areas in North America.

Big Sur is one of the most ecologically diverse areas in North America. Big Sur has its share of rare species …

Yes. In the 1800s, it attracted a lot of famous botanists because there are plants there that grow nowhere else. The Santa Lucia mountains have a lot of unique species because, at times, that area has been an island. So plants and animals that lived there have been cut off from other populations and evolved in their own direction. Probably the most famous species is the Santa Lucia fir tree, which is found in just a few canyons and nowhere else in the world. It looks like a tree in a Dr. Seuss book — the top droops over and it has these interesting cones.

Do you have a favorite spot in Big Sur?

Probably the Little Sur River Valley in the Ventana Wilderness. It has such a great combination of giant redwood trees and really dry chaparral. It’s one of those places where you have very different ecosystems within spitting distance of each other.

How about a favorite animal?

Probably golden eagles. The raptor [bird of prey] populations there are amazing. There are places where you can sit on a hillside, look out, and see five or six different raptors in a minute — golden eagles, red shouldered hawks, kites, red tailed hawks, kestrels. It’s a great show.