Give a group of high school students an opportunity to explore earth science in Arizona and they might just do it! Such is the case for 14 students from the Lawrence Academy in Massachusetts. As part of their WINTERIM break, students have to engage in some form of learning or community service experience. For these students, and the two teachers at the school who wanted to open up earth science panoramas to them, our “Geoscience in The Wild” (page 12) safari is fast becoming something far beyond anyone’s wildest expectations.
During the first two days, students learned about lightning from Ron Holle, a noted lightning expert. This has included the fact that Tucson is the lightning photography capital of the world. The landscape, coupled with typically “dry” air masses, allows for thunderstorms with high cloud bases and long cloud-to-ground lighting pathways.
Then, students visited Biosphere 2 (Fig. 2) where they explored various biomes/ecosystems in controlled settings. Students walked through a tropical rainforest, a desert, grasslands, a beach area (Fig. 3) and more, all while learning the system approach to building what might best be described as a NASA-like spaceship on Earth.
Since Earth is primarily a closed system (except for energy input from the Sun), what is here now is basically what was here when the dinosaurs roamed the Earth. This means atmospheric gases, water, overall mass of the planet and so on have remained basically the same through geologic time. Hence, when building the $150 million dollar facility some 20 years ago, engineers had to account for maintaining that constancy. Air leaks to the outside environment had to be minimized, water had to recycled and reused, and for the initial human experiment (humans are no longer studied at Biosphere), food raised and processed was all the occupants had to eat. From a communal context, everyone had to be part of the solution.
As the students discovered, even liquid human waste had to be cleansed and reused. Yuck! Yet, it worked!
While at the Biosphere, guides Franklin Lane and Yarina Hynd explained much about the Biosphere’s history and operation. Lane also provided background about desert biomes, adaptation and survival strategies and even a brief insight into the Sonoran Desert (in which the Tucson area is located). This included a discussion of the region’s mountain ranges, sky islands (isolated mountains in a sea of valleys and flat regions) and rock types.
Of course, the students, several from other countries, were fascinated with the Saguaro cacti. Although not the largest cacti in the world, these water-storing sentinels of the Sonoran Desert can reach heights of 40 to 50 feet. Due to their internal rib structure (Fig. 4), the cacti and their arms stand vertically. When external factors (e.g., disease, weather) affect the growth of the arms, the arms may sag downward. If the arms start to recurve upward, then the arm has likely survived (Fig. 5).
Students also explored geography by dissecting a Weather Channel weather broadcast segment and discussed ways to determine compass directions without the aide of a compass. While stars surfaced as a solution, so did shadows. Franklin Lane then explained that the barrel cactus (Fig. 6) always reaches for sunlight; hence, it leans southward in Arizona. The only time this doesn’t work as a direction-finder is when the cactus is shaded (e.g., by a house). Then the cactus reaches for the most available light.
Students also located scorpions in the dark using UV flashlights (Fig. 7) and searching for various rock types in daylight. This included finding a rock with seashell fossil imprints and a superb example of a metamorphic rock with folded layers (most likely gneiss).
Sunsets and sunrises (Fig. 8), various cloud formations (including lenticular clouds sitting above a mountain peak, even in the face of 60 mile per winds at altitude (Fig. 9), and a first-hand look at the Milky Way and numerous constellations, without the aid of a telescope (Fig. 10), rounded out our first two days on the road.
There is much more that has taken place during our adventure in the Grand Canyon State. Please come back and read more here at examiner.com. You can also catch up on the student experiences directly from their blog postings.
© 2013 H. Michael Mogil