IRIS and UNAVCO Facility Proposals
Draft 20120221 – Distributed to IRIS and UNAVCO Boards
EarthScope Introductory Section
EarthScope is an ambitious, multifaceted initiative to explore the structure, history and
dynamics of continents, and is the world’s first interdisciplinary continent-scale
geophysical observatory. A broad and growing population of scientists utilize data
collected by EarthScope to investigate processes that shape Earth’s modern landscape and
geological architecture, as well as produce natural resources and natural hazards.
EarthScope science topics traverse vast expanses of time, bearing on processes that
operate from the sub-second to billion-year time scale, from individual earthquakes to
stresses driving lithospheric plate deformation. EarthScope’s first target, the North
American continent, provides a vast range of geologic structures, resources, and activity,
enabling the scientific community to fully leverage the observatory’s capabilities to develop
fundamentally new insights into how Earth operates.
EarthScope comprises three interlinking components: 1) the observatory facilities
operated by the UNAVCO and IRIS consortia, 2) a research program that supports PI-led
investigations, and 3) a community that actively participates in all aspects of EarthScoperelated efforts. The EarthScope facilities acquire, deliver, and archive data, develop data
analysis products, provide logistical assistance for field instrument deployment, and
organize community forums. The EarthScope Science program at the NSF provides funding
for a broad range of PI-driven research and workshops, with a particular focus on
multidisciplinary efforts driven by EarthScope data. The EarthScope research community
is a growing, broad, and diverse body, including innovative research, informal and formal
education, and governance of EarthScope facilities. The vibrancy and success of EarthScope
depends on the observatories for stability of operations and standardization, on the
research program for financial support, and on the science community as the energy source
of innovation, discovery and communication.
EarthScope Observatories
EarthScope’s primary observatories include USArray, the San Andreas Fault
Observatory at Depth (SAFOD), and the Plate Boundary Observatory (PBO). These
observatories began operations in 2004, have evolved into an integrated system of mature
and robust facilities, and provide fundamentally important datasets that have thrust
researchers into new realms of data analysis and discovery (see below). USArray
comprises two parts: the Transportable Array, a gridded network of seismometers,
barometers, and magnetotelluric instruments rolling across the lower 48 United States and
parts of southern Canada deployed for ~1.75 years per site, and the Flexible Array, a pool
of seismic and magnetotelluric instruments used for PI-driven focused field experiments.
PBO includes a network of fixed Global Positioning System (GPS) antennas installed across
the western United States and parts of southern Alaska, with a focus on the North
America/Pacific plate boundary, including several focused GPS arrays ~1000 km along the
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diffuse deformational zone of western North America, as well as several stations deployed
in the central and eastern United States. PBO also comprises a number of borehole
strainmeters and seismometers deployed along the San Andreas Fault and Cascadia
subduction systems, and a pool of GPS instruments for use in PI-driven temporary
deployments. SAFOD, a part of the initial phase of EarthScope, successfully developed a
3.1-km deep borehole penetrating the San Andreas Fault system near Parkfield, CA.
Drilling operations extracted long sections of rock core, sampling actively slipping strands
of the fault. A high-frequency seismometer is maintained downhole, but the facility has
ceased operations otherwise.
EarthScope Achievements
EarthScope has become a national and international community platform for the Earth
Sciences. Data collected from EarthScope observatories have enabled a vast array of
scientific accomplishments, ranging from new discoveries in Earth’s atmosphere, surface,
crust, mantle, and core. Hundreds of published papers have utilized EarthScope data, and
new results enabled by EarthScope data are published weekly. EarthScope has enabled the
utilization of data processing techniques previously only available in a theoretical context,
and inspired new ways to visualize these data. EarthScope has provided the data that have
enabled scientists to generate new discoveries that mandate rewriting key portions of
Earth Science textbooks.
While many fundamentally new results enabled by EarthScope data are disciplinebased, the true strength of EarthScope has been to enable new interdisciplinary studies
that include a broad range of geology, geodesy, geochemistry, geodynamics, and geophysics.
Further, EarthScope has encouraged a new generation of young scientists to develop their
careers within the interdisciplinary framework fostered by EarthScope, and carry this
broadened perspective with them as they enter leadership positions in the scientific
community. These efforts continue to challenge the community to maintain a broad scope
in their research activities, and are essential to understanding the complex processes that
underlie dynamic Earth systems. Ongoing research enabled by EarthScope will continue to
strengthen these research directions and continue the exciting pace of new discoveries
otherwise unobtainable without an integrated observatory system.
Examples of the breadth of EarthScope-enabled discovery and transformative science
are highlighted elsewhere in this proposal. A few of these include:
 Tracking, imaging and elucidation of episodic tremor and slow slip (ETS) in Cascadia
and the San Andreas Fault systems, revealing the properties of a previously
unknown component of the earthquake cycle.
 New precise constraints on the deformation driving slip along the San Andreas Fault.
 GPS measurement of earthquake waves, introducing the era of GPS-seismology.
 Direct measurement, imaging and mapping of the patterns of active western U.S.
crustal deformation and mountain uplift in three-dimensions.
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 Unprecedented resolution in images of the structure of the western U.S. crust and
mantle, including images that reveal the fate of over 100 million years of Farallon
plate subduction.
 New images of the lithosphere/asthenosphere boundary, mantle transition zone and
structures that provide a record of western US tectonomagmatic history.
 New constraints on the location and geometry of lithospheric instabilities that
influence the dynamics of western U.S. deformation.
 Insights into the modes of deformation of the Great Basin that accommodate
gravitational collapse of the continental interior.
 New seismic constraints on deep mantle dynamics, core-mantle boundary, and core
structure.
 Unique opportunities to attract the public to exciting discoveries in Earth science
 Foundational avenues for inspiring a new generation of Earth scientists
At its core, EarthScope’s success is based on several key features. These include 1) a
vibrant research community energized to utilize EarthScope data and actively participate
in governance, 2) completely open-access data made available immediately, 3) state-of-theart facilities that are coordinated by world-class management teams, 4) community and
facility collaboration to provide a strong and diversified Education and Public Outreach
(EPO) team. The partnership between the community and the EarthScope facilities will
continue, with a special emphasis on coordinated efforts on a variety of fronts.
Building on EarthScope Success: 2013-2018
In October 2009, the EarthScope community met in Snowbird, Utah to discuss science
goals, the future of the program, and to clearly articulate its underlying scientific priorities.
From that meeting, a Science Plan for EarthScope (Williams et al., 2010) was developed that
charted the state and direction for our science. The past few years have seen the science
and vision of EarthScope continue to evolve. Portions of this proposal highlight the
direction of EarthScope-driven science, providing an update to topics in the Science Plan,
and touch on additional topics that have come to the fore since 2009. Because of the
breadth of disciplines and development of technologies that comprise EarthScope research,
sustained efforts and unique opportunities continue to advance the science of Earth
observation, modeling, integration, interpretation and dissemination of results.
Over the next 5 years, the central mission of the core EarthScope facilities, community,
and program will be to pursue these opportunities, continuing to strengthen and grow.
Growth will occur in new directions as the number of Earth science communities that are
touched by EarthScope increases, creating more opportunities for scientific discovery.
Specific tasks described in this proposal will advance EarthScope within the broad context
of:
• Reinforcing the EarthScope community. The concept of EarthScope will be further
refined as a superset of the facilities and research support program, serving as a
model for system-scale geophysical investigations of Earth processes. Integrated
support for workshops, institutes, community involvement, education and outreach
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efforts, and governance will be essential to maintain this element in continued
partnership with the EarthScope National Office and the EarthScope Science program
at NSF.
 Expanding into new regions and new data collection capabilities. The arrival of the
Transportable Array at the eastern margin of North America, as well as Alaska and
surrounding regions, will generate focus for regional activities and opportunities for
partnerships with other communities and programs such as GeoPRISMS. While the
Plate Boundary Observatory has occupied Alaska for sometime, the progress of the
Transportable Array into these areas will draw attention to these elements and
create fresh opportunities for outreach. Technological developments will also
enhance the capabilities of portions of the facility that are poised for rapid growth.
 Strengthening the integrative, analysis, and interpretive capabilities of the facility.
Open access to all EarthScope datasets is a hallmark of the project, demonstrating the
power of shared data with the community. Continued development of data products
and cyberinfrastructure is presently occurring on many fronts and all levels. Higher
level data products that utilize the expertise of community members will provide
information that is easily accessible to an increased number of users.
Beyond 2018
EarthScope has become a global standard as a broad-based community-driven
integrative research facility that provides a hub for interdisciplinary science. EarthScope
should have a continued vibrant and productive impact beyond the 2018 horizon. The
Earth system processes of relevance to the EarthScope scientific community operate on
time scales longer than the original 15-year lifespan of the facility. Tectonic deformation is
slow, and does not proceed in rates or patterns that are steady state. Earthquake cycle
deformations, which are subject to, and offer insight into, rheology of the Earth, can vary
over decades to centuries. Just as new and unexpected mechanisms of plate boundary
deformation were discovered when precise geodetic observations became available at
interannual periods (e.g. ETS), new telling modes of deformation will be revealed as
interdecadal records become available. Additionally, challenges associated with managing,
mining, and integrating very large, disparate datasets will be sequentially tackled and
solved as our cyberinfrastructure becomes more sophisticated.
References (placed at end of main document; will likely need to fill in other references
above)
Williams, M.L., K.M. Fischer, J.T. Freymueller, B. Tikoff, A.M. Tréhu, "Unlocking the Secrets of
the North American Continent: An EarthScope Science Plan for 2010-2020", February
2010, 78 pp.
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