Earthquakes occur when stress builds within rock, primarily along faults beneath the surface, to the point the rock breaks and moves. The coming decade, with near certainty, will not yield ways to pinpoint earthquakes in time and space. However, one can predict a better understanding of the buildup of stress, the transfer of stress along faults, and the complex ways the shockwaves are released when rock snaps propagate through the lithosphere and along the surface. This information will have implications for emergency planning and for improving the design and construction of earthquake-resistant structures.

Earthquake Behavior

Geoscientists in recent years have advanced their understanding of earthquake behavior in several ways. For example, the notion of fault-to-fault communication has shown that faults pass stress quite effectively at the time of a quake from one segment to another. During an earthquake, considerable stress is released as shockwaves, but some of the fault’s stress also is transferred to adjacent segments. By determining the epicenter of a quake and the direction in which the rock broke—strike slip or thrust—seismologists can calculate how much stress was shifted to adjoining rock and where. This ability allows an informed estimate of where the fault will break next, but the question of when remains unanswered.

A better determination of timing could emerge from the new ability—made possible by more powerful computers—to pinpoint and observe clusters of thousands of microquakes along a fault over time. Seismologists believe these microquakes, which are magnitude 1 to 3, represent the progressive failure of a fault. However, what triggers the fault to finally break and release its pent-up energy also remains unknown. Currently, several teams are observing clusters of microquakes on the San Andreas fault near Parkfield, California, where a moderate earthquake has been expected to occur for well over a decade.

TRENDS IN BIOMEDICAL AND AGRICULTURAL SCIENCES

Sequencing the genomes of humans and other species, coupled with proteomics and advances in bioinformatics, will reveal the genes related to diseases, alter the way physicians practice medicine, and have a major impact on the development of new drugs. The growing understanding of the complex activity inside cells will provide equally important insights, as witnessed by research in the neurosciences. Among the emerging findings is that brain cells may be capable of regenerating themselves, and there is a better understanding of proteinprotein interactions, such as those of hormones and their receptors. Biotechnology will play an increasingly important role in developing human drugs, but public resistance in places to genetically modified plants may slow its role in agriculture.



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