Drilling 35 feet to install a deep-drilled, braced GPS monument (DDBM) in California. The high stability
of the DDBMs allows for precise measurement of ground movements (millimeter per
year precision) in both bedrock and softer sediments.
EarthScope is a bold undertaking to apply modern observational, analytical and telecommunications technologies to investigate the structure and evolution of the North American continent, and the physical processes controlling earthquakes and volcanic eruptions.
This will provide a foundation for fundamental and applied research throughout the United States that will contribute to the mitigation of risks from geological hazards, the development of natural resources, and the public’s understanding of the dynamic Earth. Geological processes create the rich fabric of our landscape, from the ancient, eroded Appalachian Mountains to the younger, rugged Rockies and the volcanoes of the northwestern Cascades. Most of us rarely think about the forces that formed the majestic beauty of our national parks or produced our bountiful natural resources. Only when earthquakes rattle communities or volcanoes darken the skies are we jarred into considering the great Earth forces that fashion the terrain upon which we live, work and play.
EarthScope is inspired by the need to address longstanding and fundamental questions about the forces that continue to shape our dynamic Earth. A network of multipurpose geophysical instruments and observatories will significantly expand capabilities to observe the structure and ongoing deformation of the North American continent.
An observatory deep within the San Andreas Fault will provide direct measurements of the physical state and mechanical behavior of one of the world’s most active faults in a region of known earthquake generation.
Modern digital seismic arrays will produce three-dimensional images of North America’s continental crust and the deeper mantle on which it “floats.”
Global positioning satellite receivers, strain meters and new satellite radar imagery will measure and map the smallest movements across faults, the magma movement inside active volcanoes and the very wide areas of deformation associated with plate tectonic motion.
The Plate Boundary Observatory component of EarthScope is a geodetic observatory designed to study the three-dimensional strain field resulting from deformation across the active boundary zone between the Pacific and North American plates in the western United States. The observatory consists of arrays of global positioning system receivers and strain meters, which will be used to deduce the strain field on timescales of days to decades and geologic and paleoseismic investigations to examine the strain field over longer time scales.
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