er being the top layer of the Grand Canyon, and Zion's topmost rock layer is Bryce's bottom layer.
The canyon, carved by the river still flowing at its bottom, has many rock layers, some containing dinosaur foot prints, petrified wood and petroglyphs — markers that help geologists visualize and reconstruct the history of the zone. In some areas, huge stretches of sandstone with cross-stratification are exposed, recording the migration of ancient dunes and wind directions, and providing onlookers with a glimpse of past climates. Both of these parks are stunning examples of the tectonic forces shaping the Southwest, creating the mineral deposits exploited by mines in the area as well as their natural beauty.
The group visited Hoover Dam and water treatment facilities in Las Vegas and Henderson, Nev., to see the full cycle of water conservation and use in the Southwest. Recycling and distribution rights are highly contested issues and vital for survival in the desert. Ninety percent of water used in Las Vegas is recycled. However, more and more water is being used as the population grows, and the Colorado River alone cannot provide all that is needed. Las Vegas is looking elsewhere for rivers to divert and for vast, still untapped aquifers to the north that it can exploit.
The demand for water in the southwestern United States has been going on for a long time. A vivid example of this expansion is Owen's Lake, located near Death Valley, which once received all the water from the Owens River before it was diverted to fuel a growing Los Angeles in 1913. Today the lake has dried up and become a playa, but in the past the Owens River valley was rich agricultural land with large farms and orchards, as well as a number of nearby mines. Water and its careful allotment and use in this part of the Southwest is an example of a scarce and essential resource being managed in as sustainable a manner possible, similar to the sustainable approach Mission 2016 attempted to provide for a variety of scarce element resources.
The groups’ visit to Hoover Dam was one of the last stops on the trip. The building of the dam — an incredible feat of civil engineering that uses the Colorado River as a source of hydroelectric power — created Lake Mead, which flooded the Colorado River canyon, including settlements and towns that had formed along the river. Receding lake levels due to prolonged drought, a great source of concern, have exposed some ghost towns previously covered by Lake Mead.
This trip could not have been better engineered to supplement the Terrascope curriculum and give freshmen a hands-on learning experience about the fragility of many of the world’s natural resources. Back at MIT, these students can apply their new perspective to their studies, in particularly those students who are in the two Terrascope spring programs: Terrascope Radio and Communicating Complex Environmental Issues: Building Solutions and Communicating Ideas. Although students may have thought they had already learned about these areas, everyone took away something new from the trip. As Ana Vasquez put it: “Soon we will leave, but the Southwest will keep our steady gazes, questions and echoing steps.”