SNARF Working Group - Report of the Second SNARF Workshop

Eos Trans. AGU, 85(17), Jt. Assem. Suppl., Abstract G21C-01, 2004

First Report of the Stable North America Reference Frame (SNARF) Working Group

Blewitt, G
Email: gblewittunr.edu
Address: Mackay School of Earth Sciences and Engineering, University of Nevada, 1664 N. Virginia Street, Mail Stop 178,
Reno, NV 89557 United States

Bennett, R A
Email: rbennettcfa.harvard.edu
Address: Harvard-Smithsonian Center for Astrophysics, 60 Garden St MS 42,
Cambridge, MA United States

Calais, E
Email: ecalaispurdue.edu
Address: Purdue University, Department of Earth & Atmospheric Sciences, 550 Stadium Mall Drive,
West Lafayette, IN 47906-2051 United States

Herring, T A
Email: tahmit.edu
Address: Thomas A Herring, Room 54-618, MIT 77 Massachusetts Avenue,
Cambridge, MA 02139 United States

Larson, K M
Email: kristine.larsoncolorado.edu
Address: University of Colorado, Campus Box 429,
Boulder, CO 80309-0429 United States

Miller, M M
Email: meghangeology.cwu.edu
Address: Central Washington Univeristy, Geodesy Laboratory,
Ellensburg, WA 98926 United States

Sella, G
Email: sellaearth.nwu.edu
Address: Northwestern Univ., 1850 Campus Dr.,
Evanston, IL 60208 United States

Snay, R A
Email: Richard.Snaynoaa.gov
Address: National Geodetic Survey, 1315 East-West Highway,
Silver Spring, MD 20910 United States

Tamisiea, M E
Email: mtamisieacfa.harvard.edu
Address: Harvard-Smithsonian Center for Astrophysics, 60 Garden St MS 42,
Cambridge, MA United States

We report on the first SNARF Workshop funded by NSF EarthScope, held on Jan 27, 2004. The initial SNARF Working Group membership was approved by the UNAVCO Board and is charged with producing a standard reference frame (for studies in North America) and specifying standard procedures to realize such a frame to meet the needs of EarthScope and the UNAVCO community. SNARF is an official IAG working group under the North America Reference Frame (NAREF) sub-commission. There is also a public service element to these activities in that one objective is for SNARF to become part of the definition of the legal reference frame used in the USA and Canada (NAD83), a natural spin-off demanded by society’s increasingly sophisticated needs following on the heels of scientific progress. Through the first workshop, the SNARF WG has already begun to address the pressing needs for a North America-fixed reference frame that is stable at the sub-millimeter level, and what is involved in defining a frame with such stability. Velocity solutions from GPS networks covering the North America-Pacific plate boundary (including the Plate Boundary Observatory under construction) are most naturally expressed with respect to the stable interiors of either the North America or Pacific plates. As well as providing a common frame by which to compare results from different analysis groups, such a system makes it easier to interpret the data in terms of where the total budget of relative plate motion is accomodated, and how deep plate boundary dynamics penetrate into the plate interior. Defining a stable frame at the sub-millimeter level requires adequate characterization of kinematics at that level across a sufficiently broad expanse of what may be termed the "plate interior," which deforms due to GIA and other mantle processes, coupled with lithospheric heterogeneity. A dynamically defined velocity datum (as opposed to a purely kinematic choice) is preferable to add interpretive value to site velocities. We summarize initial findings of the workshop that begin to address these issues, and present a roadmap of what is required to realize a reference frame for stable North America.

Last modified: 2019-12-24  02:12:53  America/Denver