Recent and Current Activities
Since the completion of the Apollo program, the research agenda at the Flagstaff Field Center has diversified. Planetary geology has continued as a key element of our activities, but emphasis has shifted from the Moon toward exploration of other planetary bodies, particularly Mars. Various studies of Earth now complement the investigations of other planets. Field areas are as diverse as the ice sheets of Antarctica and the sand sheets of the Sahara Desert. Closer to Flagstaff, field studies are designed to help understand physical and chemical processes that shape and modify continents, thus contributing to national requirements for resource evaluation, natural-hazard recognition, hazard-reduction planning, and the like. The following summarize a few of the more recent lines of research at Flagstaff.
A geologic map is simply a chart or depiction of the areal distribution of different kinds of rock units and the breaks (faults), folds, and warps that deform these units from their original shapes. A geologic map usually is printed on a topographic (contour) map base, so that a user can see the shape of the landscape along with the distribution of the rock units on one sheet of paper.
Many projects at Flagstaff include geologic mapping, simply because such mapping provides the fundamental basis for evaluating and interpreting other categories of data. For example, consider the lava flows and cinders erupted about 900 years ago at Sunset Crater, just a few miles northeast of Flagstaff. Within the context provided by a geologic map of that area, we have learned not only the volume and geologic character of the erupted products, but also that some of the cinders that blanketed the area buried prehistoric dwellings and generally disrupted human life. Thus, a geologic map can be a powerful research tool that also has practical applications.
All of the United States and many other parts of the world are covered by high-quality topographic maps, but a special challenge for geologists mapping other planets is the lack of a topographic base on which to compile geologic information. Another obvious challenge is the lack of rock samples from other planets. Because of the great expense and time needed for missions to the Moon and planets to pick up samples, it is more practical to send camera-carrying probes into orbit around other worlds or probes to land on them. In addition, careful study of images of extraterrestrial landscapes and comparisons with our own can lead to remarkably detailed and sophisticated interpretations of planetary geology. The effectiveness of this type of "indirect" geologic mapping was established by the Apollo missions; rock samples brought back from the Moon generally confirmed predictions made from observations through Earth-based telescopes.
Rocks and minerals can be studied in great detail from samples collected at the Earth's surface, but scientists generally must create models or hypotheses when they try to understand subsurface geologic conditions. Direct study of rocks in the subsurface as a test of such models is possible only through trenching and drilling. As a result, drilling devoted to geologic research, rather than to resource exploration and exploitation, is now a standard technique in many countries around the world. Flagstaff scientists participate in such drilling projects, which test models about the formation of geothermal and mineral-deposit systems, and also about stresses generated along earthquake-prone faults. Some of the research drill holes are as deep as 6 miles. Drilling, although an expensive scientific tool, may be the only effective means of learning how much geothermal energy is in the crust beneath us.
Arid regions (places where rainfall is insufficient to grow crops without irrigation) make up about 80% of the Earth's rangelands, including most of the American West. These regions are especially vulnerable to loss of soil by wind erosion. Parts of five large arid regions (the Great Basin and the Upper and Lower Sonoran, Mohave, and Chihuahuan Deserts) are within a few hours drive from Flagstaff--in Arizona, California, and New Mexico. Since about 1980, automated "weather" stations have been transmitting data from these arid regions to the Flagstaff Field Center. The data are gathered by solar-powered sensors and relayed by satellite to the Center. In addition to sensors that gather standard meteorological information, an instrument has been developed to detect blowing sand, thus allowing scientists to correlate wind-caused soil erosion with other climate variables.
The Grand Canyon
As one of the scenic and geologic wonders of the world, the Grand Canyon is a natural laboratory for research by earth scientists at the Flagstaff Center. They have learned much about how rock strata have been deposited through time, how rivers carve canyons, and how water behaves in rapids. Public concern over how operation of the Glen Canyon Dam may affect conditions downstream in the canyon has prompted an ambitious program of multi-disciplinary and multi-agency research by USGS geologists and hydrologists working with biologists and archaeologists. Data are gathered to help decision makers plan an appropriate balance between "natural" conditions in the canyon and conditions that attend the presence of a dam and the large hydro-electric plant at Glen Canyon, just upstream.
An adequate supply of fresh water is fundamental to life on Earth. Thus, continuous monitoring of the quantity and quality of both surface and subsurface waters is essential. Hydrologic projects of the USGS staff in Flagstaff include maintaining a northern Arizona network of stream-gaging stations where water flow is continuously charted, as well as periodically measuring the depth to ground water in more than a hundred wells of the region. Water samples from the streams and wells also are regularly analyzed for quality. These monitoring efforts are supplemented by appropriate research and published reports and scientific papers. All results are used to assist water-resource managers at local, State, and Federal levels to plan, design, and operate dams, water-well fields, systems of water distribution and treatment, and other water-related operations.
Planetary geology continues as a major research effort at the Flagstaff Field Center. The main objectives are (1) to study the origin and evolution of the planets and satellites of the Solar System, (2) to formulate theories to describe geologic processes operating on these bodies, (3) to develop increasingly sophisticated techniques of remote sensing and image processing to aid in interpretation of planetary surfaces, and (4) to produce mosaics of images returned from space missions, as well as topographic and geologic maps of planetary bodies.
Current projects focus on Mars, the satellites of Jupiter, Saturn, and Uranus, and, once again, the Moon. As vast amounts of information in digital form are returned periodically to Earth from robotic spacecraft, the data are processed by computer systems and programs developed at Flagstaff to form images that can be interpreted in terms of the history that produced planetary surfaces. Planetary scientists depend heavily on their terrestrial experiences when interpreting the images, and, conversely, surface features well developed and preserved on extraterrestrial bodies can provide scientists with a better understanding of the geologic history of the Earth.
The USGS at Flagstaff interacts with citizens at large by communicating the results of projects to interested parties in many ways. Research results and databases are routinely reported through talks and poster materials at meetings. This information is also made available as maps and papers published in a variety of journals and as compact disks produced both within and outside the USGS. The production of videos is becoming increasingly popular as a means to report results. Posters and accompanying text that illustrate and describe the results of current projects adorn the walls of hallways in office buildings. The USGS participates in the planning and presentation of the annual Flagstaff Festival of the Sciences and holds open houses and other events during the Festival.
Increasing interaction with students and various public groups is creating broader awareness, knowledge, and interest in the earth and planetary sciences. Presentations by scientists and staff in classrooms, at fireside campground gatherings, and for civic groups help broaden awareness. Science teachers in the Flagstaff and nearby school systems are given a series of lectures and related field trips. In addition, college students are recruited actively for part-time employment working with USGS staff, which provides help needed for various project leaders and simultaneously stimulates student interest and participation in the earth and planetary sciences.