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GeoPRISMS Community Seismic Experiment along the Eastern North American Margin

Concordia Room, Westin San Francisco,

50 Third Street, San Francisco, CA

Thursday, December 8, 2011, 11:30am – 1:30pm

Conveners: The GeoPRISMS Office on behalf of the ENAM Community

AgendaMeeting objectivesMeeting report

11:30 | Introduction and background

11:30 | Motivation, objectives and approach – Harm van Avendonk & Beatrice Magnani

11:40 | Summary of Fall ENAM workshop and selected focus areas – Vadim Levin

11:50 | KProposed USGS Extended Continental Shelf surveys – Daniel Brothers, Uri ten Brink

12:00 | Potential industry partnerships – Harm van Avendonk

12:10 | What is a community experiment – Donna Shillington

Data processing, format, and access | Donna Shillington, Beatrice Magnani

12:20 | Discussion

12:30PM | Possible Experiment Scenarios – N. Miller, Daniel Brothers, J. Kluesner

End-Member Models

One high-priority, margin normal, wide-angle onshore-offshore transect
Multiple onshore-offshore wide-angle surveys (spacing, orientation)

Intermediate and alternate models, e.g.,

Comprehensive coverage, shallow MCS survey
Several wide-angle transects

Discussion

1:00 PM | Moving Forward with Community Involvement

Logistical constraints (ship scheduling, instrument pools, permitting)
Offshore logistics – Donna Shillington & Harm van Avendonk
Onshore logistics – Beatrice Magnani

Discussion – Making it happen

Who will be the “heroes”
Preparing and submitting a community proposal to NSF
Building an industry consortium
Communication and participation (e.g., on-line forum)

Wrap-up

The imminent arrival of the EarthScope transportable array (TA) and selection of the Eastern North American Margin (ENAM) as a GeoPRISMS primary site, are defining exciting new research opportunities along this margin. In addition, the USGS is responsible for coordinating the collection of seismic data along the eastern seaboard as part of the US Extended Continental Shelf Project under the UN Convention on the Law of the Sea. Tentatively, USGS surveys in the ENAM area will take place in 2013 using the R/V Langseth seismic vessel, providing potential opportunities for piggy-back experiments.

This convergence of interest in ENAM, and the presence of the R/V Langseth in Atlantic waters, offers a unique opportunity to conduct a community seismic experiment along the ENAM, benefiting a large number of researchers, especially students and early-career investigators. Improved seismic imaging of the margin, both shallow and deep, onshore and off, would address a wide range of GeoPRISMS and related research objectives. It can yield a backbone dataset for studying the deep structure of the margin, its structural and stratigraphic architecture, ongoing geodynamic processes, economic potential, and many other aspects.

If you would like to learn more, participate in, and/or contribute to planning discussions about the scope and objectives of such a community seismic experiment, please register to attend the luncheon. The luncheon discussion will include:

Identifying and prioritizing scientific objectives for an ENAM seismic experiment
Possible end-member survey scenarios (e.g., minimum cost vs. comprehensive coverage)
How to engage and coordinate with potential partners (USGS, Industry)
Data access requirements and expectations (and schedules)
How to prepare and submit a community proposal

Figure 1: Map of Discovery Corridors in ENAM focus area. The red shaded area is the target of the USGS seismic program on the U.S. Extended Continental Shelf. ECMA = East Coast Magnetic Anomaly, BSMA = Blake Spur Magnetic Anomaly.

U.S. Earth Scientists Prepare for a Community Seismic Experiment at the ENAM Primary Site

2011 AGU Fall Meeting San Francisco, CA

Harm Van Avendonk¹, Beatrice Magnani²

¹University of Texas at Austin, ²University of Memphis

Eastern North America (ENAM) was chosen as a GeoPRISMS Rift Initiation and Evolution primary site because it represents a mature rifted continental margin in which the entire record of continental break-up and rifting is preserved. The rifting history along ENAM is well recorded in basin stratigraphy and the underlying crustal structure, although subsidence, sediment transport and fluid flow are presently the dominant geological processes along the margin. The study of old rifted margins is often challenged by a thick cover of sediments, which masks much of the deep crustal structure. This is also true for ENAM; however, over the next few years, unprecedented opportunities exist to carry out focused geophysical studies, revealing both shallow and deep structures of ENAM in greater detail.

The convergence of two activities along ENAM serves to frame data-gathering opportunities. In 2013, the EarthScope Transportable Array (TA) will arrive in ENAM, and the USGS is planning a marine seismic reflection and a limited refraction study of the Extended Continental Shelf (ECS) along ENAM onboard the seismic vessel R/V Marcus Langseth, possibly as early as 2014. In addition, there is renewed interest from energy companies in the exploration of ENAM . At the joint Earthscope-GeoPRISMS Science Workshop on Eastern North America, held at Lehigh University in October 2011, discussions among various academic, government and industry scientists led to the suggestion that a community active-source seismic experiment could improve our understanding of the deep structure and evolution of ENAM, and make the best use of existing resources and upcoming opportunities. The planned USGS active-source seismic operations over the ECS provide part of the immediate impetus for such an experiment; however, the possibility exists to extend some of the proposed USGS profiles landward to image deep margin structures and obtain important seismic velocity constraints. Given the limited mission of USGS ECS surveys, funding to extend these profiles and record air-gun shots on-land must come from NSF, possibly with some industry sponsorship.

A GeoPRISMS-sponsored luncheon was held in San Francisco on December 8, 2011, during the AGU Fall Meeting. About 30 scientists met to discuss further the conceptual framework of a community proposal for an ENAM active-source seismic experiment. Several scenarios were discussed, from minimum-cost to comprehensive coverage. The latter could include onshore-offshore operations, e.g., air-gun shots from the R/V Marcus Langseth recorded not only by its 8-km-long multichannel seismic streamer, but also by co-linear OBSs and by EarthScope Flexible Array seismometers, deployed along on-land extensions of selected marine seismic transects. In addition, land-based shots along these transects could be recorded by Flexible Array seismometers as well as by OBSs, providing reverse coverage. Additional PI-driven piggyback deployments offshore and onshore could be designed to take further advantage of the community seismic effort. The consensus at the luncheon was that such a joint seismic experiment is feasible and opportune; however, the timing may depend on the final schedule for the USGS seismic program.

The GeoPRISMS ENAM primary site spans much of the U.S. and Canadian Atlantic margins, from Charleston to Nova Scotia. However, budgetary and logistical constraints require that the target area of a community seismic experiment be much smaller. The area of interest for the planned USGS ECS seismic study lies between the Outer Blake Ridge offshore South Carolina in the south and Cape Cod to the north (Figure 1). Within this region, the planned ECS seismic survey consists of profiles spaced 60 nautical miles apart, spanning the interval from the continental shelf break to the 200 nautical mile limit. To meet GeoPRISMS objectives, some of these profiles would be extended landward across the shelf, and onshore, where air-gun shots would be recorded by land stations.

At the EarthScope-GeoPRISMS Science Workshop at Lehigh, participants identified a few major corridors where dense data acquisition would benefit integrated studies of rifted margin processes (Figure 1). The “Philadelphia” and “Richmond” corridors exhibit pronounced along-strike structural variations in the Appalachians; thus, seismic transects that cross the shoreline in these two areas may yield insights into the role of inherited orogenic structure on the development of rift half-grabens, such as the Culpeper and Hartford basins, and the nature of syn-rift magmatic wedges that define the continent-ocean transition offshore. To the south, a transect in the vicinity of Charleston, SC, would image the transition between the Carolina Trough and the Blake Plateau, clarifying the structure and origin of basement in this area. In addition, the gas hydrate province of Blake Ridge is an important site for the assessment of geohazards on the continental slope. Comparisons of the deep-seismic structures along the northern and southern corridors would provide a view of regional differences in extension and magmatism during the opening of the Atlantic, helping to explain the linkages between these processes.

To have a true community experiment, broad participation from the U.S. scientific community is necessary. Researchers interested in participating in an ENAM community seismic experiment are invited to help with the (a) design of the active-source seismic data acquisition plan, (b) proposal writing, and (c) staffing of the data acquisition teams on-land and offshore. The involvement of graduate students and postdocs in this effort is very important, as these early-career scientists represent the core of the future GeoPRISMS and EarthScope communities. In the sprit of community science, we envision rapid data release and open data access following the experiment, enabling many members of the scientific community to participate in seismic data analysis and interpretation. Science proposals to use the seismic data could be submitted to NSF once the data are collected.

Although funding of the USGS seismic study of the ECS is currently uncertain, this field program is tentatively being planned for 2014. To create a successful partnership with the USGS in 2014, collaborative proposals must be submitted to the NSF GeoPRISMS and EarthScope Programs solicitations in 2012, on July 2nd and July 16th, respectively. Over the next few months, we hope to engage our colleagues in discussions about ENAM science priorities, and we welcome insights and contributions to the ENAM community seismic experiment proposal. Consider contributing through the GeoPRISMS forum site or by contacting us directly.

Collaborative Efforts in the East African Rift System

Fillmore ABC, Grand Hyatt San Francisco

345 Stockton Street, San Francisco, CA

Thursday, December 12, 2013, 6:30 pm – 9:30 pm

Conveners Part 1: C. Ebinger, T. Fischer, S. Kattenhorn
Conveners Part 2: D.S. Stamps, W. Nelson, R. Moucha, A. Nyblade

AgendaMeeting objectivesMeeting report

PART I – Opportunities and Challenges in GeoPRISMS EAR Focus Site

6:30 – 6:40 | GeoPRISMS introduction – Peter van Keken
6:40 – 6:50 | Existing data, ongoing projects and opportunities for capacity-building – Cindy Ebinger
6:50 – 7:00 | Opportunities for collaboration with geothermal exploration groups – Tobias Fischer
7:00 – 7:10 | Brief scientific overview and logistical challenges – Simon Kattenhorn
7:10 – 7:30 | Question and answer session

BREAK

PART II – Collaborative Efforts for Synoptic Studies of the East African Site

Part I – The Eastern Branch Focus Site

The GeoPRISMS focus site and affiliated sites in the East African Rift (EAR) system pose tantalizing research opportunities, as well as logistical challenges for new data acquisition, and access to existing in-country data sets (e.g., aeromag, reflection).

Coordination of research and educational activities with African geoscientists may be challenging, both in terms of finding partners, and liaising with the relatively small research community. Coordination of field programs, and ideas for collaborative training opportunities enables fuller, more rewarding interactions with our international colleagues. Our mini-workshop is planned to coordinate and facilitate planning and training activities in or concerning the Eastern rift focus site. Our goals are to review existing data sets and active projects, including rapidly expanding geothermal exploration, paleoanthropological studies, and geohazards initiatives (e.g., GEMS), to facilitate team-building and collaborative experiments, and to share experience. Early-career scientists in particular are encouraged to attend. Prior to the AGU meeting, we will work with GeoPRISMS to develop a web-based template for region-specific planning in Tanzania, Kenya, Rwanda, and Ethiopia. We encourage others to add to this template, which will be hosted by GeoPRISMS. Early identification of project partners enables the African colleagues time to apply for in-country or USAID funds to support their full participation in field and laboratory research.

Part 2 – Synoptic Studies of the East African Site

The East African Rift System (EARS) offers an unparalleled opportunity to synthesize disparate studies that produce data pertinent to understanding the fundamental geodynamics of continental rifting. In 2012 during the GeoPRISMS EARS planning workshop, the community identified synoptic investigations along the entire EARS as a Collaborate Target of Opportunity. The initial questions posed in the implementation plan suggested studies aimed at understanding the wide variations in the origin, composition, and timing of volcanism, the rate and distribution of strain along and across the rift systems and large-scale pre-rift structure and dynamics underpinning the rift system. However, at the time of the workshop, the details of the implementation plan were not identified. In addition, there may be interest in investigating other processes that span the entire length of the EARS (e.g. natural hazards, tectonic-climatic interactions, large-scale mantle dynamics, etc.) that were not discussed at the planning workshop. Due to the size and complexity of the rift-system and the challenges involved in coordinating multi-country fieldwork, a community effort will be required to address synoptic studies of the EARS. To encourage community discussion, forward-thinking, and to capitalized on the timing of GeoPRISMS funding cycles, we as a community need to identify and define possible system-wide, multi-disciplinary, collaborative investigations in the EARS. The timing is also ideal for combining efforts to leverage the NSF PIRE program which will accept proposals in July 2015. To this end, we will host a timely, structured mini-workshop with the following goals:

Identify specific synoptic studies of interest to the GeoPRISMS community.
Identify existing datasets and what data sets are needed to address multi-disciplinary synoptic studies.
Assess interest in a community proposal for submission to the July 2015 GeoPRISMS solicitation.
Provide a networking opportunity to foster mentoring of young investigators and team building.

Collaborative Efforts in the East African Rift System

AGU Fall Meeting 2013, San Francisco, USA

Conveners Part 1: Simon Kattenhorn¹, Cynthia Ebinger², Tobias Fischer³
Conveners Part 2: D. Sarah Stamps⁴, Wendy Nelson⁵, Robert Moucha⁶, Andy Nyblade⁷

¹University of Idaho; ²University of Rochester; ³University of New Mexico; ⁴MIT; ⁵University of Houston; ⁶Syracuse University; ⁷Penn State University

The AGU GeoPRISMS Mini-Workshop on Collaborative Efforts in the East African Rift System was held Thursday evening, 12 December 2013 at the Grand Hyatt hotel in San Francisco during the AGU Fall Meeting. It was well attended with 50 participants, 9 of whom were graduate students and 7 were postdoctoral researchers. This workshop had two sections sharing a common theme of bringing scientists together to discuss collaborative efforts underscored by the GeoPRISMS East African Rift System (EARS) implementation plan.

Part 1. The Eastern Branch Focus Site

Ongoing research programs in the Kenya-Tanzania rift sector were briefly reviewed as a foundation for scientific planning, and as experiential learning in terms of data acquisition and collaboration. These studies show high levels of seismicity, fault activity, and gas emissions in this magmatically-active region, which spans basins that formed at 25 Ma to < 1 Ma. The age span enables studies of rift initiation, propagation, and evolution within one sector. Presenters outlined existing data sets acquired by academics, petroleum, mineral, geothermal exploration, and governmental organizations.
Coordination of field programs and collaborative training opportunities enables fuller, more rewarding interactions with our international colleagues and provides more effective liaison with the relatively small EAR research community. For example, Fischer outlined strong support offered by geothermal exploration and production teams in Kenya.
Presenters outlined the procedure to obtain research permits in Kenya and Tanzania, as well as potential collaborating institutions. Attention was drawn to the USAID PEER program, which enables African collaborators to seek separate funding for enrichment of participation in NSF-funded research.

Mini-Workshop “Collaborative Efforts in the East African Rift System”

Part 2. Synoptic Studies of the East African Site

The GeoPRISMS initiative offers an unprecedented opportunity to synthesize EARS data and models for an improved understanding of the fundamental geodynamics of continental rifting. In 2012, during the GeoPRISMS EARS planning workshop, the community identified synoptic investigations along the entire EARS as a Collaborative Target of Opportunity. The initial questions posed in the implementation plan motivate studies of the mechanisms enabling rifting of cratonic lithosphere, the origin, composition, and timing of volcanism, the rate and distribution of strain along and across the rift systems, and large-scale pre-rift structure and dynamics underpinning the rift system.
Part 2 of the Mini-Workshop centered on obtaining feedback from participants in real-time. We presented three questions for discussion and report responses to each:
What questions are of interest to the community that concern synoptic studies of the EARS?
What datasets exist and what is needed to address system-wide studies of the EAR?
Is there interest in a community-driven proposal?
Given the recorded responses at the AGU Mini-Workshop, there is some interest within the GeoPRISMS community to develop a community-driven proposal to address synoptic studies of the EARS as evidenced by 50% of the responses.

Acknowledgements

We thank the GeoPRISMS Program of the National Science Foundation for funding this workshop, the moderators who volunteered to record participant responses in real-time to on-line documents using their personal computers, and the GeoPRISMS chair for providing Internet connectivity during the workshop.