Teaching Geography Workshop 2: Latin America – Part 2: Ecuador

BINKO: In this half hour, we are investigating one of the Earth's most powerful and dramatic processes, volcanoes. Our case study takes us to Ecuador, high in the Andes, to a region known as the Valley of the Volcanoes. Volcanoes and associated earthquakes occur as a result of movement of the Earth's tectonic plates. These vast slabs of earthen crust float on the planet's molten core. Seismic activity is concentrated at the edges of these plates, and where the plates collide, mountains crash upwards. Such events are reflected in geography Standard 7: The physical processes that shape the patterns of the Earth’s surface. One of today's objectives is for you to be able to explain how physical systems, such as volcanoes, influence the Earth's features. These physical systems also have great impact on surrounding human populations. The people in our case study live with the constant threat of volcanic eruptions.

Standard 15, how physical systems affect human systems, addresses some of the human issues associated with natural hazards. There are both benefits and consequences of living near a volcano. Volcanoes create fertile soil, but they also pose risks. As you view the upcoming case study, watch for these positive and negative influences of physical systems on human activity.

In Ecuador, geographers monitor seismic activity and promote effective procedures to ensure the safety of people living nearby. Natural hazards are not preventable, and though our predictive science is improving, the precise timing and magnitude of volcanic eruptions remains elusive. As you view, look for ways that technology helps our understanding of natural hazards. As we see in the case study we can sometimes manage the risks, but there are costs to every solution.

Finally, in our classroom segment, we will see how one teacher adapts the inquiry method to provide students of all abilities with a richer understanding of what it means to live near a volcano.

NARRATOR: The Andes Mountains of Ecuador. Beautiful yet ominous. 200 of these peaks are volcanoes, some with active craters like this one. 30 could erupt again. In 1985, a massive eruption in neighboring Colombia melted snowfields, causing mudflows that killed more than 23,000 people. Throughout South America, scientists studied the tragedy and vowed to prevent the next one.

They may get their chance here, in Ecuador. The Tungurahua volcano threatens a town of 17,000 at the base of the mountain. It is called Baños. Although Baños is very near the equator, its elevation in the Andes gives it a mild climate.

(\children shouting playfully\)

Add spectacular scenery and some geothermal hot springs and you have a vibrant tourist economy.

On the surrounding hillsides, adequate rainfall and fertile volcanic soil sustain agriculture. But the same natural forces that sustain the economy are also a source of danger. Hoping to avoid a tragedy, geographer Patty Mothes maps and monitors several volcanoes for Ecuador's Geophysical Institute, including Tungurahua. She is looking for any changes that might signal an eruption.

MOTHES: And one of these ways that we do that is to put a prism that's highly reflective, or a number of prisms up on the flanks of the volcano, and then, shooting with this very high-powered laser beam...

NARRATOR: The beams reflect off the prisms and back to Patty's measuring device. It can detect subtle changes in the shape of the mountain, changes that may forecast an eruption and save lives. Their concern is based on history. Inside a church, a mural recalls a deadly eruption in 1773. It happened again in 1886 and 1918. So why do people live in such a dangerous place? Some people simply cannot afford to move, due to limited economic means. Others have businesses and farms here, with family roots going back many generations. Here, as elsewhere, decisions to live near hazards result from some attachment to place balanced against the very real risks. Human perception of those risks often leads to denial.

“No es peligroso, no...”

TRANSLATOR: No, it's not going to be dangerous for Baños when the Tungurahua erupts again. There are some big ravines over there and the mouth of the volcano is facing that way, so there is no danger that it will spew this way.

NARRATOR: In a small eruption, he might be right. A major blast of lava flows would likely move west and miss the center of town. But shooting down these ravines, pyroclastic flows could incinerate part of the town in an avalanche of superheated gas and ash. It's happened before.

“Siempre por meses después...”

NARRATOR: Mothes triesto communicate the hazardto young civil defense workers.

“Primeros todos bajaren en una velocidad muy, muy alta.Puede ser mucho más rápido...”

TRANSLATOR: They can go much faster thana horse can run, or a person.We are talking abouthundreds of kilometers per hour. The burning lava can reachthe bottom of the mountainin less than five minutes.It's somethingthat's truly formidable.

NARRATOR: The team distributesevacuation maps around townto diagram escape routes.To gather more cluesof an impending disaster, Mothes and her team bury sensitive seismic monitorsall around the volcanoto record telltale earthquakes.The signals are radioedback to the institute,where each new installationtests the equipmentand the scientists' nerves.

(\equipment whirring\)

MOTHES: Whee!

Good work.

NARRATOR: Mothes and geologist Peter Hall scrutinize the volcano, hoping that they won't someday have to make the tough call. Eruptions can kill and destroy. But evacuations cause great personal and economic loss. What if they sound the alarm and Tungurahua does not actually blow up? Will people believe them the next time, before it really does? Suddenly, after monitoring the mountain for five years, their theoretical problem has become alarmingly real. (\rumbling explosions echoing\)

MOTHES: In September 1998 our existing seismic network on the volcano began to register a greater number of fracture-type earthquakes beneath the volcano.

NARRATOR: The next August, Tungurahua releases a column of steam thousands of feet in the air. The deadly vapor accompanies more earthquakes and sulfur emissions. It's time for the scientists to go public.

MOTHES: On the 10th of September, we decided we had better call a yellow alert. Which changed the way everybody looked at the volcano.

NARRATOR: Soon, people could not only see but feel the danger.(\volcano rumbling\) The violent mountain throws out clouds of volcanic ash, suffocating crops and animals. (\volcano rumbling\) Now, ordinary citizens could taste the peril lurking in the mountain. Their fears are reflected in Patty's tilt meters, which show powerful forces pulsing just below the surface. She believes the surge is caused by molten magma rising to the peak.

MOTHES: We knew that magma was moving, but we'd not been able to confirm visually that it was there near the summit.

NARRATOR: Suddenly, it surfaced. Fiery magma glowing in the midnight sky. (\loud boom\) (\crowd exclaims; whistling\) (\people cheering\)

HALL: The incandescence that we saw on the 11th of October led us to believe that an eruption could come very soon.

“Buenos días, cómo Montecito...”

NARRATOR: Mothes and Hall need a closer look at the smoking crater. Here, they confront the odds of disaster.

HALL: Given that yes, now we have magma in the crater, all the way to the summit of the mountain, all we need is some big explosions to get that lava out and down the flanks of the volcano.

NARRATOR: But rather than send out a red alert, the scientists still show restraint. So they are surprised in October when the president of Ecuador comes to Baños and overreacts to their less acute orange alert.

HALL: He decided right then that we need an evacuation, we need it now.

NARRATOR: The military forces 25,000 tourists and residents to evacuate all areas surrounding Tungurahua.

(\sirens wailing\)

“En lo de doña Inés; yo me voy ahora.” (\man making announcement\over loudspeaker\)

NARRATOR: Even more disruptive: they have 36 hours to leave.

MOTHES: The Institute had recommended that this evacuation could take place over a period of days, not in a day and a half. Because we didn't see the volcano was yet that ready to erupt.

NARRATOR: They also disagree with the government about a partial evacuation.

MOTHES: We have always had an opinion that the people living on the west side are the most vulnerable to these pyroclastic flows but there may have been other villages that we'd have said, "No, these people can probably be left there."

NARRATOR: Instead, the government moved everyone out--some to shelters far from the blast zone. Outside of Baños, the army erects roadblocks to hold back residents eager to go home. But the scientists read new and ominous messages from deep in the mountain.

“Cuando hay más magma, significa más gas.”

NARRATOR: And more gas signifies new trouble.(\loud explosion\) It is not the cataclysmic eruption, but a signal of future danger. At the top of the cone, cooling magma seals off the building gas trapped below. (\volcano rumbling\) The pressure builds up so much it just bursts the seal. (\explosions booming\)

NARRATOR: In blast after blast, Tungurahua throws room-sized blocks all over the mountainside. What Mothes fears now is a blockage and buildup so large it will suddenly release the full fury deep in the Earth.

MOTHES: So this was a scenario that we thought was likely, and the clock is ticking. There's 25,000 people evacuated, people are clamoring to get back, and you're trying to read this volcano that has not erupted since 1918.You need to make certain statements about what you think is going to happen.

NARRATOR: But what will happen becomes increasingly unclear. Activity on the mountain plateaus, but does not end. Meanwhile, people have been away from their homes and jobs for 2½ months. Crops and animals perish from neglect, and still no major eruption. Then, in December, the media reports that soldiers are looting residents' homes. The news touches off a riot. (\shouting\)

MOTHES: They came in on busloads-- about 3,000--with sticks and stones and machetes and they drove the military off. They took some military hostage also. And then they had a truce that they signed that night with the governor, saying that we will take back our town, that we do this on a voluntary basis, and that the government is not responsible for our well-being.

NARRATOR: The citizens of Baños are happy to be home, relieved that Tungurahua did not kill humans. But are they safe? And what do they think of their government and the scientists? Peter Hall warns that the last fatal eruption occurred almost two years after the initial blasts.

HALL: We keep telling the people, "Don't forget what happened in 1916 and 1918."We went for a long period without activity and the big eruption came late. If a new eruption threatens, the scientists may have time to issue another alert. The question is, who will heed the call?

GIL LATZ: This case study provides a dramatic illustration of Standard 15: how physical systems affect human systems. The town of Baños exists in part to exploit Tungurahua's thermal activity, and in part due to the area's rich volcanic soil. And as we see how people there reap the location's benefits, we can also learn how they attempt to mitigate the risks. South America has a wide range of physical environments. Its mountains and lowlands extend from the equator to the frigid south. And, as is true throughout the world, these physical environments shape human settlement and activity.

In Chile, farmers take advantage of micro-climates in the foothills of the Andes to grow table grapes just in time for the Christmas holiday season in the lucrative North American market. The temperate climate and fertile soils of southern Brazil and adjacent states provide a substantial agricultural base for the large population that has grown there, especially as found in the world's third largest city, Sao Paulo. Centered in Brazil's north, Amazonia is the largest and most important rain forest in the world. From the 1970s and '80s, the Brazilian government promoted development there by building transportation networks and encouraging migration into the region. Scientific concern is twofold: rain forest destruction will lead to the loss of an estimated one-half of the world's plant and animal species; and loss of this fragile ecological zone may have serious effects on climate patterns that nourish life across the Earth. In the final analysis, geographers argue, we need to achieve a difficult balance. On the one hand, the needs of local populations who depend on the region for their livelihood. And, on the other hand, the global concern that rain forest depletion may adversely affect the entire world.

BINKO: Is there any geophysical phenomenon more interesting to children or adults than an exploding volcano?

In the following lesson, Carole Mayrose capitalizes on her students' natural curiosity as she teaches some important ideas about the impact of physical systems on human activity. She asks her students this primary geographic question: Is there a relationship between the location of earthquakes and volcanoes? As they gather and analyze their information, Carole also asks her students to consider whether they might like to live near a volcano.

After viewing this segment, you should be able to explain how teachers can use student curiosity as an entry point for teaching about physical features. This classroom has a number of inclusion students-- that is, students with special needs or requiring special attention. As Carole teaches, pay particular attention to the skills she uses to promote success in a supportive yet rigorous learning environment. Watch for the many ways inquiry instruction can be adapted to accommodate the learning requirements of students at all levels. Whether or not we teach inclusion classes, we all encounter pupils who can benefit from Carole's techniques.