Sierra Nevada EarthScope Project (SNEP)

An NSF research highlight!

The REPORT OF THE ADVISORY COMMITTEE FOR GPRA PERFORMANCE ASSESSMENT FY 2007 highlighted SNEP as the significant earth science highlight in the NSF's goal of improving research infrastructure: "Imaging of a Foundering Lithosphere (0454524; 0454535; 0454554) Drs. Hersh Gilbert of Purdue University, Craig Jones of University of Colorado, Tom Owens of University of South Carolina, and George Zandt of University of Arizona analyzed NSF's EarthScope seismic data to identify a region where the mantle lithosphere is currently being stripped from beneath the Sierra Nevada batholith. As our understanding of processes related to the removal of mantle lithosphere improves, the important role played by lithospheric removal in continental deformation becomes increasingly apparent. Along the central portion of the western foothills of the Sierra, small earthquakes occur deep within the crust. These events may result from stresses associated with the lithospheric removal process. Resolution of EarthScope data has allowed a significant advance in understanding of the tectonics of mountain building and plate interactions. "

Who:

above is list of PIs/co-Is (in bold) and their postdocs and students. SNEP participants are also working with the Sierran Drips CD Project. We have also had help in the field and lab from IRIS interns Amanda Thomas and Scott Burdick (whose primary work was SNEP) and Christina Viviano and Monica Guerra (whose primary work was elsewhere) in 2005 and Will Levandowski (2006; he joined up with CU in 2008) , USC undergraduates Katrina Byerly, Nickles Badger, and Will Huff , CU graduate students Joya Tétreault, Gaspar Monsalve, Tom de la Torre, Chris Harig, USC staffers Charlie Groves, Philip Crotwell, U of A graduate students Andy Frassetto, Josh Calkins, Arda Ozacar , and CU volunteer Kristen Marano. Derry Webb from PIC helped in the field and many others at PASSCAL also have helped. (I think that is 26 people who have been in the field under the SNEP banner....)

SNEP mailserv is at South Carolina (along with list archives).

What, When, and Where:

~48 broadband seismometers were deployed from spring 2005 to September 2007 from about Kings Canyon National Park north to Honey Lake and west from the Central Valley into the Great Basin.

Analysis responsibilities are distributed with certain institutions taking the lead on different approaches:

Known problems, Phase I: (removal): 53, GPS removed by bear, 62 whole packer pulled by bear. (July service): 75 panel crushed; 65 GPS rare lock after 3/06, 14 GPS failed 1/2/06. (June '06 service): 64 was down much of winter, 55 sensor was way out of center, both noisy on horizontals??, 45, 46 and 56 down significant time (45 panel lost), 56 panel was partially loose, 86, 24 heavily damaged, 43 lost parameters and int batt dead, 23 battery dead (green box failure?), 63 junky sensor and flooded, 23 bad green box. (May '06 service) 52, 74, 22, 12, 84, 95, 67, 66, 57, 47, 36 all had problems at some level. flooded sites were 12, 52, 53, 95; others GPS and/or power problems. (over winter) 34 disk filled; (Jan) 42 stolen (replaced); 11 flooded (moved). 51,52,71 had leveling problems during high rain. Some east side GPS problems; (Oct '05) 74 opened by bear (lost power but recovered OK when reconnected); 21 has high frequency noise (no obvious solution), seems to have tilting problems (repeatedly loses horizontals), 22 had 6 second (?) timing error; repaired 8/3/05, 64 might need extra panel.

Phase II problems: Pullout, September 2007: 65-GPS died 07.056 (vault flooded and DAS died 07.133; sensor pins corroded) 87-GPS dead after 07.187 A8-Ch 3 dead 07.142, DAS stops dumping 07.178 B5-sensor or A/D noise after 07.176 C6-vault uncovered, noise on horizontals C8- GPS died after 24 hours and station down at 07.151 G5-Ch 1 dead after 07.246 May 2007: 12-powered down, short in sensor cable, 24-dead after one dump 55-plug pulled 87-GPS died 06.283 97-disk full 98-minor power outage towards end? A7-GPS out for 53 days B5-power system down after 07.068 B6-coherent noise on horizontals B7: power system failures after JD 94. E7-outages JD 30-60. January 2007: F9, very low sunlight, hole in DAS vault lid-now two panels and batteries, new lid; D4, D5, C4, E5, E4 frequent tilt-out of horizontals (autocentering frequency improved). GPS at E6 appeared to be misbehaving-replaced. Bear damaged B5 (repaired). C3 flooded; moved to shed above ground. 12 had no power--pin sleeve in solar panel cable was pushed back into connector. E7 was in the dark; panel moved 60' farther north. Disk problems from Jan. run disks from G9, E9. Power outages noted 96, E5, E4, E7, A4, F9 (more minor outages elsewhere). Stations we didn't try to visit (19): G7, F8, C8, C6, B6, A5, 87, 86, 85, 75, 65, 64, 55, 34, 24, 14, 84, 74, and 63. So 33 of our 52 stations were visited.

Other maps

• SNEP phase 1 + 2 on a topographic base, 2/07. 13 Mb. Should have correct phase 2 locations and only include active stations.
• SNEP phase 1 + 2 on a geologic base, 2/07. 14 Mb.

Map of SPE and SNEP2005 deployments on geologic base, with ES stations as of April 2006 (click for pdf version):

Map of all Sierran portable passive deployments, 1988-2007, and US Array stations: (click for larger version) (need to adjust for final SNEP deployment)

Why:

To better understand the physics of removal of mantle lithosphere and the consequences of such tectonism.

Meetings:

• Seismology planning meeting, Tucson, late January, 2005
• Sierran Drips workshop, October 20-22, 2005, Park City, UT
• IRIS Workshop, Jun 8-10, 2006.
• Joint SNEP/Sierra Drips CD meeting, Sorensen's Resort, Hope Valley, CA, October 8-10, 2006.
• SNEP special session at 2007 Fall AGU (session T31 : Foundering Lithosphere: Observations and Implications, with a Focus on the Sierra Nevada)
• Fall meeting with Sierra Drips CD, Tucson, Arizona, 2-4 November 2008.
• Final workshop for Sierra Drips, Boulder, Colorado 8-10 November 2009.

Proposal documents:

The 2004 Earthscope proposal

Animation of Sierran uplift histories (a figure from Jones et al)--shockwave.

Fieldwork:

Field materials now on an archive page

Photo websites:

• Joya's collection of photos (2005) (offline now)
• Amanda Thomas had photos from her IRIS internship, apparently offline
• Short movie (5 Mb QuickTime) of horsepack deployments (mainly 75, a little of 54)
• Jones photos from the SNEP14 and 34 deployment in late September
• June 2006 service photos
• Andy's photo collection (2006)
• January 2007 service photos (CHJ)

Cartoon of installation

Calendar: (Older calendar for reference)

Resources:

Maps:

• BLM map viewer (shows townships, land management agencies, etc.)
• USGS National Map viewer (a number of different overlays possible)
• Gateway to national geospatial data clearinghouse (ESRI portal seems to work better than USDA)
• USGS Seamless data distribution server
• California GIS page (digital raster graphics for most of CA)
• DOE landuse/geothermal resources map for California (pdf)

GMT files: (and a simple script to build a station map)

• SNEP evenly spaced (45 sites)
• SNEP plus Bigfoot in area
• US Array stations (from website, as lon, lat, ID)
• Trinet (CIT/SCEC) stations (so. CA) (lon, lat, station ID, station text, elevation)
• Trinet stations with BHZ channel (almost same as above) (so. CA)
• UNR broadbands reporting to IRIS (lon, lat, ID) (Nevada, eastern CA)
• UC Berkeley broadbands (lon, lat, elev, id, network id, station text, channels, on year, on JD, on time, off year, off JD, off time)

Publications:

• Jones, C. H., Reeg, H., G. Zandt, H. Gilbert, T. J. Owens, J. Stachnik, P-wave tomography of potential convective downwellings and their source regions, Sierra Nevada, California, Geosphere, 10 (3), doi:10.1130/GES00961.1, 2014
• Levandowski, W., C. H. Jones, H. Reeg, A. Frassetto, H. Gilbert, G. Zandt, and T. J. Owens, Seismological estimates of means of isostatic support of the Sierra Nevada, Geosphere, 9(6), 1552-1561, doi: 10.1130/GES00905.1, 2013.
• Gilbert, H., Y. Yang, D. W. Forsyth, C.H. Jones, T.J. Owens, G. Zandt, and J.C. Stachnik, Imaging lithospheric foundering in the structure of the Sierra Nevada, Geosphere, 8, p. 1310-1330, doi:10.1130/GES00790.1, 2012.
• Frassetto, A., G. Zandt, H. Gilbert, T.J. Owens, and C. Jones, Lithospheric Structure of the Sierra Nevada from Receiver Functions and Implications for Lithospheric Foundering, Geosphere, vol. 7 (4) pp. 898-921, doi: 10.1130/GES00570.1, 2011. (DOI not working; Geoscienceworld link)
• Frassetto, A., G. Zandt, H. Gilbert, T.J. Owens, and C. Jones, Improved Imaging with Phase-Weighted Common Conversion Point Stacks of Receiver Functions, Geophysical Journal International, doi: 10.1111/j.1365-246X.2010.04617.x, 2010.
• Gilbert, H., C. Jones, T. J. Owens, G. Zandt, Imaging Sierra Nevada lithospheric sinking, EOS, 88 (21), pp. 225 & 229, 22 May, 2007.
• Jones, C. H., H. Gilbert, G. Zandt, T. Owens, The Sierra Nevada EarthScope Project: A first report from the broadband FlexArray, IRIS Newsletter, 2006 volume, issue 3, pp. 12-14. (small or large pdf version of full newsletter from IRIS)

In process:

S-wave paper, local earthquake paper (both hopefully showing up in 2019).

Theses:

• Levandowski, W., Geophysical investigations of the origins and effects of density variations in the crust and upper mantle beneath the western and central United States, 2014
• Reeg, H., Seismic structure of the crust and upper mantle of the Sierra Nevada, California, M.S. thesis, Univ. Colorado, 139 pp., 2008
• Frassetto, A., Teleseismic studies of the North American Cordillera: Evaluating the changing structure, composition, and fabric after subduction, Ph. D. thesis, Univ. Arizona, 2009 (info link)

Abstracts:

AGU, San Francisco, Dec. 15-19 2008--see list of presentations of potential interest to SNEP

• Frassetto, A., H. Gilbert, G. Zandt, T. J. Owens, and C. Jones, Seismic character of the crust and upper mantle beneath the Sierra Nevada, Eos Trans. AGU, 89(53), Fall Meet. Suppl., Abstract S32B-05, 11:20 am
  
• H. Reeg., C. H. Jones, H. Gilbert, T. J. Owens, and G. Zandt, Tomographic observations connecting convective downwellings with lithospheric source regions, Sierra Nevada, California, Eos Trans. AGU, 89(53), Fall Meet. Suppl., Abstract S32B-06.11:35 am
  
• T. J. Owens, I. D. Bastow, N. Badger, G. Zandt, C. Jones, and H. Gilbert, Shear wave anisotropy beneath the Sierra Nevada: Implications for lithospheric foundering and mantle flow, Eos Trans. AGU, 89(53), Fall Meet. Suppl., Abstract S33B-1956 , PM poster
• Ryan, J. C., A. Frassetto, O. Hurd, G. Zandt, H. Gilbert, T. Owens, and C. Jones, Focal Mechanisms for Deep Crustal Earthquakes in the Central Foothills and Near Yosemite National Park in the Sierra Nevada, California, Eos Trans. AGU, 89(53), Fall Meet. Suppl., Abstract S33B-1957, PM poster
• Levandowski, W., H. Reeg, C. H. Jones, G. Zandt, T. J. Owens, and H. Gilbert, Constraints on lithology of downwelling lithosphere from the Sierra Nevada, California, Eos Trans. AGU, 89(53), Fall Meet. Suppl., Abstract U51B-0044, AM poster
• Gilbert, H., Y. Yang, D. W. Forsyth, C. H. Jones, T. J. Owens, and G. Zandt, Bounds of foundering in the southern Sierra Nevada, Eos Trans. AGU, 89(53), Fall Meet. Suppl., Abstract U54A-04, 4:45 pm

GSA, Houston, October 2008

• Zandt, G., H. Gilbert, C. Jones, and T. J. Owens, Insights on Lithospheric Delamination from the Sierra Nevada Earthscope Project (SNEP), Geol. Soc. Am Abstr. Prog., 40 (6), p. 396, abstract 263-7, 2008.

IGC, Oslo, August, 2008

• Owens, T., H. Gilbert, G. Zandt, C. Jones, Lithospheric Foundering:  Constraints from the Sierra Nevada EarthScope Project, 33rd Intl. Geol. Congress, Oslo, Norway, Aug. 2008.

AGU, San Francisco, Dec. 2007

• Badger, N. B.,  I. D. Bastow, T. J. Owens, G. Zandt, C. H. Jones, and H. Gilbert, Shear wave anisotropy beneath the Sierra Nevada range: Implications for lithospheric foundering and upper mantle flow, Eos Trans. AGU, 88 (52), Fall Mtg. Suppl., Abstract T33A-1149, 2007.

• Reeg, H., C. H. Jones, H. Gilbert, T. Owens and G. Zandt,Teleseismic Travel-Time Tomography of the Sierra Nevada and its Foundering Lithosphere, Eos Trans. AGU, 88 (52), Fall Mtg. Suppl., Abstract T33A-1150, 2007.

• Zandt, G., H. Gilbert, A. Frassetto, T. Owens, and C. Jones, Insights on Lithospheric Foundering from the Sierra Nevada Earthscope Project (SNEP) , Eos Trans. AGU, 88 (52), Fall Mtg. Suppl., Abstract T31E-01, 2007.

AGU, Acapulco, 22-25 May 2007

• Levandowski, W., Beam-formed Receiver Function Analysis From the Southern Sierra Nevada, CA: A Moho Hole??, Eos Trans. AGU, 88(23), Jt. Assem. Suppl., Abstract T23A-08, 2007.

AGU, 11-15 December 2006

• Byerly, K., T. J. Owens, H. Crotwell, J. Julia, H. Gilbert, G. Zandt, C. H. Jones, Bulk crustal properties of the Sierra Nevada, Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract S43A-1358, 2006.
• Bastow, I. D., T. J. Owens, G. Zandt, C. Jones, H. Gilbert, J. Julia, SKS splitting analyses from the Sierra Nevada Earthscope Project: Insights into lithospheric foundering, Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract S43A-1361, 2006.
• Gilbert, H., C. Jones, T. Owens, G. Zandt, Observations of lithospheric foundering, Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract S54A-01, 2006.
• Frassetto, A., I. D. Bastow, O. Hurd, G. Zandt, H. J. Gilbert, T. J. Owens, and C. H. Jones, Crustal anisotropy, deep crustal earthquakes, and the Moho hole beneath the west-central Sierra Nevada, California, Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract T52B-02, 2006.
• Hurd, O., A. Frassetto, G. Zandt, H. Gilbert, C. Jones, and T. J. Owens, Deep Crustal Earthquakes and Repeating Earthquakes in the West-Central Sierra Nevada, Western USA, Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract S43A-1360, 2006.

• Levandowski, W., C. H. Jones, Receiver functions from medium aperture broadband beams and the Moho of the Sierra Nevada, California, Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract S54A-03, 2006 (won best student presentation, seismology section)

IRIS Meeting, June 8-10, 2006, Tucson, AZ

• Zandt, G., "Southern Sierras", 2:05-2:25 June 8. Powerpoint is here and note there are 2 movies needed as well in the same directory.
• US Array posters 10:30 am - 12:00 noon

AGU, 5-9 December 2005

• Burdick, S., Zandt, G., Gilbert, H., Jones, C., Owens, T (2005) Moho Structure of the Central Sierra Nevada From an EarthScope Flex Array Deployment, Eos Trans. AGU, 86(52), Fall Meet. Suppl., Abstract S41E-05 .
• Byerly, K., Julia, J., Owens, T J., Gilbert, H., Zandt, G., Jones, C. (2005) Sierra Nevada Earthscope Project: Constraints on the Sierran Seismic Structure From Regional Waveform Modelling, Eos Trans. AGU, 86(52), Fall Meet. Suppl., Abstract S51E-1062
  
• Gilbert, H, Hurd, O, Jones, C H, Owens, T J, Zandt, G (2005) Observations of deep intra-plate earthquakes along the western foothills of the Sierra Nevada, Eos Trans. AGU, 86(52), Fall Meet. Suppl., Abstract S51E-1067.
• Thomas, A, Jones, C, Reeg, H, Gilbert, H, Zandt, G, Owens, T (2005) Teleseismic travel times, the Isabella anomaly, and the missing Moho, from the Sierra Nevada EarthScope experiment, Eos Trans. AGU, 86(52), Fall Meet. Suppl., Abstract S51E-1061

GSA, October 2005

• Jones, Craig H, G. Zandt, T. J. Owens Jr., and H. Gilbert, The Sierra Nevada Earthscope project: Motiviations, status, and early results, Geological Society of America Abstracts with Programs, 37 (7), 59, 2005.
  

IRIS Meeting, 19-21 June 2003, Fish Camp, CA: (click for abstract)

• Mihai N. Ducea, Jason Saleeby, Crustal production and loss in continental magmatic arcs; Evidence from the Sierra Nevada (talk, 4:30 Saturday, Salon V and VI)
• Craig H. Jones, G. Lang Farmer, Peter Molnar, Jeffrey R. Unruh, Delamination of the Sierra Nevada: Seismological observations and tectonic implications (poster) [pdf version of poster online, 2.3 Mb, click here]
• George Zandt, Hersh Gilbert, Thomas J. Owens, Drip Drag? (poster)

Reprints/Preprints of interest:

• Boyd, O., C. H. Jones, A. F. Sheehan, Foundering lithosphere imaged beneath the southern Sierra Nevada, California, USA, Science,  305, 660-662, 2004. (Supplementary material)
• M. N. Ducea, Constraints on the bulk composition and root foundering rates of continental arcs: A California arc perspective, J. Geophys. Res., 107 [B11], 2304, doi:10.1029/2001JB000643, 2002
• M.N. Ducea, S. Kidder, G. Zandt, Arc composition at mid-crustal depths: Insights from the Coast Ridge Belt, Santa Lucia Mountains, California, Geophys. Res. Letts., 30 [13], 1703, doi: 10.1029/2002GL016297, 2003.
• Jones, C. H., G. L. Farmer, and J. R. Unruh, Tectonics of Pliocene removal of lithosphere of the Sierra Nevada, California, Geol. Soc. Am. Bull., 116 (11/12), 1408-1422, 2004.
• Molnar, P. H., and C. H. Jones , A test of laboratory based rheological parameters of olivine from an analysis of late Cenozoic convective removal of mantle lithosphere beneath the Sierra Nevada, California, USA, Geophysical Journal International , doi: 10.1111/j.1365-246X.2004.02138, 156 , 555-564, 2004.
• S. K. Park and M. N. Ducea, Can in situ measurements of mantle electrical conductivity be used to infer properties of partial melts? J. Geophys. Res., 108 [B5], 2270, doi:10.1029/2002JB001899, 2003
• S. K. Park, and B. P. Wernicke, Electrical conductivity images of Quaternary faults and Tertiary detachments in the California Basin and Range, Tectonics, 22 [4], 1030 10.1029/2001TC001324, 2003.
• S. K. Park, Mantle heterogeneity beneath eastern California from magnetotelluric measurements, J. Geophys. Res., 109, B09406, doi:10.1029/2003JB002948, 2004.
• J. Saleeby,M. Ducea, D. Clemens-Knott, Production and loss of high-density batholithic root - southern Sierra Nevada, California, Tectonics, 22 [6], 1064, doi:10.1029/2002TC001374, 2003.
• J. Saleeby and Z. Foster, Topographic Response to Mantle Lithosphere Removal in the Southern Sierra Nevada Region, California, Geology, 32 [3], p. 245–248; doi: 10.1130/G19958.1, 2004.
• G. M. Stock, R. S. Anderson, and Robert C. Finkel, Pace of landscape evolution in the Sierra Nevada, California,
  revealed by cosmogenic dating of cave sediments. Geology, 32, [3], p. 193–196; doi: 10.1130/G20197.1, 2004.
• G. Zandt, The Southern Sierra Nevada Drip and the Mantle Wind Direction Beneath the Southwestern United States, International Geology Review (Thompson Volume),45, 213-224, 2003.
• Zandt. G., H. Gilbert, T. J. Owens, M. Ducea, J. Saleeby, and C. H. Jones, Active foundering of a continental arc root beneath the southern Sierra Nevada, California, Nature, 431, 41-46, 2004. (Supplementary material)

Some other info on Sierran Paradox experiment webpage

This material is based upon work supported by the National Science Foundation under Grants Nos. 0454535, 0454524, and 0454554 to CU, USC, and U of A, respectively. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

C. H. Jones | CIRES | Dept. of Geological Sciences | Univ. of Colorado at Boulder