1. What are the EarthScope Facilities?

The EarthScope Facilities have three main components: the Plate Boundary Observatory (PBO), San Andreas Fault Observatory at Depth (SAFOD), and USArray. PBO comprises a network of about 1200 stations covering the 48 contiguous states and Alaska, including continuously operating GPS, borehole and laser strainmeters, seismometers, and tiltmeters. SAFOD provides physical samples and seismic, geodetic and electromagnetic data from the San Andreas Fault near Parkfield, California. USArray comprises a nationwide long-term seismic Reference Network supported by multiple agencies; the 400-station Transportable Array that is slowly marching from west to east and will reach the East Coast in 2012; and a backbone network of seven magnetotelluric observatories. PBO and USArray also include portable equipment pools for use in temporary experiments proposed by individual scientists; maintain integrated data management systems; and support education and outreach activities including teacher training and curriculum development, sponsorship of summer intern and research experiences for undergraduates, and technical workshops and software development.

2. How many employees does the EarthScope Facility have?

The EarthScope Facility supports a total of about 110 full-time equivalent positions across the U.S., with primary offices in Alaska; California; Colorado; New Mexico; Oregon; Washington, D.C.; and Washington State. The 110 positions also include a number of field engineers at work across the country. In addition, more than 125 students have been involved in construction and operation of the EarthScope Facility to date.

3. What is its annual budget? How much did it cost to build?

The EarthScope Facility total construction budget from 2003-2008 was $197 million. The current operations and maintenance budget is $25 million/year, and the anticipated total budget for the first five years of operations (2008-2013) is $126 million.

4. How many national and international collaborations/groups are involved in the EarthScope Facility?

Please note that, in addition to those listed below, there are dozens of individual private landowners who have given permits to install EarthScope Facility stations on their land. There are also numerous State and local government agencies, private companies, and US educational institutions that have been involved with constructing, operating, and maintaining the EarthScope Facility or with oversight activities.

The EarthScope Facility is operated, maintained, and managed for NSF by two non-profit corporations that each represent a large scientific consortium: the Incorporated Research Institutions for Seismology (IRIS) and UNAVCO. IRIS is responsible for USArray and has 114 full members; UNAVCO is responsible for PBO and SAFOD and has 94 full institutional members and 70 associate members. In addition, multiple national and international groups are or have been involved in various ways with the EarthScope Facility, including:

• US Federal Agencies: National Science Foundation; Bureau of Land Management; Department of Energy; NASA; NOAA; US Geological Survey; US Fish and Wildlife Service; US Forest Service.

• International Collaborations: Australia (Commonwealth Scientific and Industrial Research Organisation [CSIRO], GTSM Technologies); Canada (Geological Survey of Canada, Pacific Geoscience Center, Queens University, University of Alberta, University of British Columbia, University of Calgary, University of Manitoba, University of Quebec at Montreal); Chile (University of Chile); China (China Earthquake Administration, China Institute of Geophysics, China Seismic Array); Japan (Geological Survey of Japan); Mexico (Centro de Investigacion Cientifica y de Educacion Superior de Ensenada [CICESE], Universidad Nacional Autonoma de Mexico [UNAM]; New Zealand (Victoria University).

• Other: European Plate Observing System; Federation of Digital Seismographic Networks; International Continental Drilling Program; International GNSS Service; International Union of Geodesy and Geophysics.

5. What is the physical size of the EarthScope Facility?

This is a difficult question to answer because the Facility is so distributed, but perhaps the single best answer is the area of the US States and Territories covered by the EarthScope Facility network. The EarthScope Facility has, or will have, stations in all 48 contiguous States, Alaska, and Puerto Rico; this is a total of 3.8 million square miles (9.8 million square kilometers). Of course, individual stations are much smaller than that, and the sum of the area covered by each individual station would be much smaller.

6. Are there other metrics that relate to EarthScope that help convey how big it is?

• The Facility includes nearly 4000 instruments of various types.

• The Facility has collected over 67 terabytes of data to date and adds another terabyte on average every six weeks.

• More than 1200 different groups downloaded data from the Facility in just the last quarter of 2010.

• During the construction of the Plate Boundary Observatory, EarthScope crews drilled boreholes totaling over 19 km in depth.

• The SAFOD borehole is over 3.2 km long and ends about 2.7 km below the surface (the borehole is vertical for the first 1.5 km, then is tilted for the remaining length).

• EarthScope Facility crews have driven well over 1.5 million miles in the construction, operation, and maintenance of the Facility.