are many major challenges facing solid-earth scientists as they serve societal needs. Prominent among these are:
to provide sufficient resources—for example, water, minerals, and fuels
to cope with hazards—for example, earthquakes, volcanoes, landslides, tsunamis, and floods
to avoid perturbing geological environments—for example, soil erosion, water contamination, improper mining practices, and waste disposal; and
to learn how to anticipate and adjust to environmental and global changes.
An important force driving earth science research is human curiosity regarding our origins, evolution, and the processes that shape our environments.
Programs designed to improve the human condition, whether related to resources, hazards, or environmental change, depend on the results of basic research aimed at expanding our understanding of the Earth's processes. Therefore, the GOAL OF THE SOLID-EARTH SCIENCES is:
to understand the past, present, and future behavior of the whole earth system. From the environments where life evolves on the surface to the interaction between the crust and its fluid envelopes (atmosphere and hydrosphere), this interest extends through the mantle and the outer core to the inner core. A major challenge is to use this understanding to maintain an environment in which the biosphere and humankind will continue to flourish.
New concepts and methodologies are emerging that permit the synthesis of solid-earth science data on a global scale. The new capabilities allow construction of testable models of interaction among the many subsystems that form the whole earth system. This global view was heralded by the plate tectonics revolution, which recognized that material making up the rigid outer plates comes from the interior at suboceanic spreading centers, is modified at the surface, and either returns to the interior at subduction zones or is added to the continents. Current research into the interconnected systems aims at developing an understanding of convection in the solid interior, the specific plate-driving mechanism, and the connection between convection and the hydrosphere and biosphere, including long-term atmospheric and oceanic changes.
Pure and applied earth sciences are intimately interwoven.
Twenty-five years ago our understanding of the global system was revolutionized by plate tectonics and the recognition of a highly mobile outer shell of the Earth. This breakthrough, as well as the continued demand for water, mineral, and energy resources, led to a surge in the number of qualified researchers. These researchers have access to advanced instrumentation in laboratories, in the field at the Earth's surface on land and sea, and in aircraft and in space. Computational capabilities have revolutionized the handling of the vast amounts of data generated in earth science research and facilitated the rapid construction and testing of sophisticated models.
Although recent years have, in some sense, been the best of times with the introduction of new concepts and sophisticated observing systems, the increasing calls for guidance or predictions or solutions for major societal problems require an even more dedicated cadre of earth scientists and facilities to meet the challenges of the next century. The expectation continues that the earth science community in the United States will play a leadership role in global scientific cooperative research. This report addresses the research areas, their applications, and the personnel and facility requirements for the U.S. earth sciences to fulfill national and international expectations.
During most of the twentieth century, the mineral and energy extractive industries employed most of the geologists and geophysicists and commanded a large fraction of the basic and applied research conducted. Because they are fundamentally cyclical industries, their support of research has waxed and waned with economic fluctuations. The resource industries are now restructuring, and there is a growth of employment and research opportunities related to environmental matters and engineering geology, including hydrology and waste isolation. These areas may become the