Seismic Reflection and Refraction

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Field Geophysics at SAGE: Strategies for Effective Education

BRAILE, Lawrence W.; BALDRIDGE, W. Scott; JIRACEK, George R.; BIEHLER, Shawn; FERGUSON, John F.; PELLERIN, Louise; MCPHEE, Darcy K.; BEDROSIAN, ; Paul A.; SNELSON, Catherine M.; and HASTEROK, Derrick P.

Larry Braile

[email protected]

http://web.ics.purdue/~braile SAGE website: http://www.sage.lanl.gov/

Science for Planet Earth

A Brief History of SAGE

(Summer of Applied Geophysical Experience) 2012 – Our 30 th Year!

SAGE is a unique program of education and research in geophysical field methods for undergraduate and graduate students from any university and for selected professionals. The core program is held for four weeks each summer in New Mexico and for an additional week in the following academic year at San Diego State University for U.S. undergraduates supported by NSF. Each year 25-30 students participate in SAGE after being selected from a wide range of large and small colleges and universities.

Since SAGE was initiated in 1983, 730 students have participated in the program. NSF Research Experience for Undergraduates (REU) funding for SAGE began in 1990 and 319 REU students have completed SAGE through 2011.

Main Objectives of SAGE

      Teach the Major Geophysical Exploration Methods (Seismic, Gravity, Magnetics, Electromagnetics) Apply the Methods to the Solution of Specific Problems (Environmental, Archaeological, Hydrologic, Geologic Structure and Stratigraphy) Integration of Methods, and Geology Present Career Options in Geophysics Student Professional Development Research in the Rio Grande Rift Area

SAGE Program Schedule Summary

Summer (~4 weeks, Rio Grande rift area, New Mexico)

 Exploration geophysics theory and applications,    classroom/lab/discussion (7 days).

Geophysical field work (1 day – near-surface archaeological site, 5 days – basin scale field area).

Geology field trips (3 days). Data processing, analysis, interpretation, preparation of oral and written reports – interpretation and method teams (5 days).

  Student presentations and written reports (2 days).

Presentations by visitors – industry, government, academia (mostly evening talks, equivalent of 2 days).

Follow-up workshop for REU students in January

 R & R days (2 days).

Additional analysis and interpretation of the data from summer and preparation of abstracts for presentation at professional meetings (5 days).

Geophysical Exploration Methods

Near-surface Archaeological geophysics

– seismic refraction, electromagnetics (EM), magnetics, GPR

Basin scale field area

– Gravity/GPS Seismic refraction CMP seismic reflection profiling Magnetics Magnetotellurics (MT) Transient Electromagnetics (TEM) Seismics Magnetics GPR EM

Gravity/GPS

Gravity Stations and Map

Magnetics

Archaeological Site - GPR

Kiva?

GPR Image 1 m

Seismic Reflection and Refraction

“Flagging” Vibroseis Truck

Driving the Vibe Truck – “Priceless”

SAGE Student Driver – Whoa!!!

Seismic Reflection and Refraction

Fault Refraction Reflection shot gathers

Seismic Reflection and Refraction

Processed and Stacked CMP Reflection Section Seismic data acquisition in the “doghouse”

Electromagnetics

1800 m N

Electromagnetics

2-D Model of TEM Soundings 1700 m 1600 m 1500 m 0 m Distance S Blue is resistive 200 0 Red is conductive 3400 m

SAGE 2010 Geophysics Highlights Blue is resistive

MT sounding indicating midcrustal conductor at ~ 20 km depth.

West-East CMP stacked seismic reflection record section. La Bajada fault plane reflections on right.

Successful Strategies (developed and refined over the years)

1. Learning by doing; immersion ( intense program/schedule ).

2. Mix of lecture/discussion; field work; data processing and analysis; modeling and interpretation; presentation of results.

3. Two tier team approach ( interpretation/integration teams – each team includes person representing different methods; technique oriented teams ). Provides focus, in depth study, opportunity for innovation ( technique oriented teams ), and promotes teamwork and multi disciplinary approach ( interpretation/integration teams ).

4. Emphasis on presentations ( discussion on how to prepare and deliver a 12 minute talk ) – teams (all team members) make presentation; each student completes a written report (SEG expanded abstract format); professional development.

Successful Strategies (developed and refined over the years)

5. Experiment Design Discussion – safety, constraints, data quality/quantity, research objective, educational experience, set parameters for survey, why multidisciplinary?, etc. Students drive discussion.

6. Multiple methods (each student gains experience with all methods), and information on careers (students really appreciate); networking .

7. Student experiences and interactions (many of the students become friends for life).

8. Measures of success - High rate of continuation to graduate school (about 75% of SAGE undergraduates), support and feedback from industry participants and visitors , student evaluations at end of program, presentations at professional meetings, publications, faculty evaluation of student work.

SAGE Students – Geology Field Trip

SAGE website: http://www.sage.lanl.gov/

Additional SAGE Information:

8:00 AM – 12:20 PM, Tuesday, Dec. 6, MCS Halls A-C T21A-2316.

Seismic and Gravity Investigation of the Eastern Boundary of the Santo Domingo Basin, Rio Grande Rift, New Mexico

(Poster) 8:00 AM – 12:20 PM, Tuesday, Dec. 6, MCS Halls A-C H21E-1170.

Geophysical Characterization by the SAGE Program of a Newly Proposed, Low Temperature-EGS Prospect in the Central Rio Grande Rift, New Mexico

(Poster) SAGE 2012 Information: http://web.ics.purdue.edu/~braile/sage/SAGE2012.pdf

SAGE website: http://www.sage.lanl.gov/ This PPT: http://web.ics.purdue.edu/~braile/sage/FieldGeophysics.ppt

Challenges for the Future

Maintaining funding Program is expensive (low student/faculty ratio, all off campus, geophysical equipment and field work).

Support for SAGE (funds and “in-kind” support): NSF REU program, Los Alamos Natl. Lab, US DOE, USGS, Industry, Society of Exploration Geophysicists, participating universities.

Recruitment We continue to have many excellent student applicants However, we have had limited success in increasing the diversity of SAGE students.

Added a component of SAGE to involve Native American students from New Mexico Pueblos.

Maintaining momentum and continuously enhancing program Requires significant commitment of faculty.

Enhancements each year based on student feedback and faculty consideration of successes and failures.

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