Drilling into the San Andreas Fault at Parkfield Calif. An international team of scientists are embarking on a project to drill an angled hole through a seismically active portion of the San Andreas Fault Zone, creating a San Andreas Fault Observatory at Depth (SAFOD). In the summer of 2004, SAFOD began drilling directly through the fault to a depth of 3.2 kilometers, in order to obtain samples and make geophysical measurements within and adjacent to the fault zone, and to install instruments to continuously monitor variations in rock deformation and other parameters during the earthquake cycle. When complete, SAFOD will provide direct information on the composition and mechanical properties of fault rocks; the nature of stresses responsible for earthquakes; the role of fluids in controlling faulting and earthquake recurrence; and the physics of earthquake initiation and rupture. By observing earthquakes up close, SAFOD will mark a major advance in the pursuit of a rigorous scientific basis for earthquake hazards assessment and prediction. In a modern-day journey to the center of the Earth, geologists are exploring the structure and evolution of the North American continent at scales from hundreds of kilometers to less than a millimeter from the structure of a continent, to individual faults, earthquakes and volcanoes. The project is called EarthScope. With approximately $200 million in funding from the National Science Foundation (NSF), EarthScope began development in 2004, and will continue over a five year period. It is expected to operate for an additional 15 years. EarthScope is using multiple technologies to explore the structure and tectonics of North America. For example, a four-kilometer deep observatory was drilled directly into the San Andreas fault to measure the physical conditions under which earthquakes occur there. One of 875 permanent Global Positioning System (GPS) stations has been installed, which can measure relative distance changes of less tha
