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What's Inside Letter
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A Letter from the Department Chair Tim Lowenstein The chairman’s baton has officially been passed from Bob Demicco to me. I am proud to say that the job has been made easy by a healthy and thriving group of professors, staff, graduate students and undergraduates. It is time to start showing off some of the great accomplishments by members of our department, beginning with highlights of research by two of our faculty: Jeff Barker and Bob Demicco on pages 3 and 5, respectively, of this Newsletter*. This year we nominated David Jenkins for the Chancellor’s Award for Excellence in Research and Jeffrey Barker for the Chancellor’s Award for Excellence in Teaching. They will (we hope) join recent awardees Dick Andrus, Steve Dickman and Tim Lowenstein. That is impressive considering our faculty numbers 13! More accolades to John Bridge for the publication of his exhaustive book “Rivers and Floodplains” and Bob Demicco’s (with BU professor George Klir) “Fuzzy Logic in Geology”. All of our faculty continue to do great research all over the world, along with advising and teaching, and you can read about that in the faculty news. Graduate students Ramon Aguirre and John Rayburn have been awarded University Awards for Excellence in Teaching and Research this year. Congratulations to them and to all our students (past and present) who make things happen in Science 1. Without students, the halls of Science 1 would echo. Other good news: Joe Graney was awarded tenure and promotion to associate professor. Joe, Karen Salvage, and Sid Mitra (who joined our faculty in January 2003) are the core of our growing program in environmental science that we are quite proud of. We continue to offer a strong graduate and undergraduate program in most disciplines of geology, and our graduates have been very successful in getting jobs or continuing their education. We really appreciate all the support from alumni who actively seek our help in placing our graduates in jobs with their firms. I want to personally thank many of you who donated money for the “Van Fund” and to the department. That money will help us purchase a new van this spring and will add to our “fleet” such as it is. Many of you will fondly remember field trips in the 1980 brown van and the 1985 “Old Red” van. I recall a trip to Clarksville Cave when the water pump on “Old Red” exploded, leaving us shaken and stranded in Cobleskill. Believe it or not, those rusting hulks are still parked on campus, but we can’t really use them for more than local trips. You will be happy to hear that we will be offering a new course, “Field Methods in Geoscience” beginning next fall. I know that most alums probably found field trips one of the most enjoyable experiences of their education at BU, and we hope to expand that part of our program. Many of us regularly attend the Geological Society of America Annual Meeting and we usually have a pretty good party there. If you ever have a chance to go to GSA, please join us at the Alumni party. Finally, thanks to David Jenkins for putting together this Newsletter and to Jeff Barker who has added a huge list of alumni on our web page. Check it out. *Editor's Note: Beginning this year the Geo-Bing Newsletter will be including the highlights of the research of several faculty members in our department, taken primarily in alphabetical order. We hope you find this slightly more in-depth view of faculty research to be an interesting addition to the Newsletter. |
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Modeling
earthquake ground motion by Jeffrey S. Barker |
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| When I joined the faculty here in 1987, my research areas in seismology were earthquake source modeling and regional wave propagation modeling. We’re pretty good at that now, with errors between observed and theoretical ground motions of a few percent at worst. However, seismologists routinely ignore the effect of the wave propagation in 3-D structures immediately beneath the site of interest (a seismic station, a building, a dam, etc.), and this site effect can be responsible for errors of hundreds of percent in ground motion amplitude and duration. The reason we have ignored it in the past is that it is very difficult to compute. | ||
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the worst-case location for earthquake site effects occurs in Mexico City.
This is the second largest metropolitan area in the world (after Tokyo)
and is located 300-400 km from the Mexican subduction zone. Nevertheless,
Mexico City suffered severe damage and deaths during the 1985 Michoacan
earthquake. The city is built on a dry Pleistocene lakebed, with thick,
soft clays overlying thick volcanic ash deposits. These soft layers cause
amplification and increased duration of shaking. The period of resonance
of waves within these layers, about 3 seconds, is the same as the period
of resonance of buildings 5-10 stories in height. These buildings suffered
most of the damage in 1985. A few years ago, when I was on sabbatical in Grenoble, France, I started analyzing data recorded on a seismic array right in downtown Mexico City. |
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| The array consisted of three stations in a triangle separated by about 100m, and recorded ground motions from a handful of large subduction zone earthquakes from the south and west. After filtering the data to include primarily the periods of damaging ground motions (2-4 sec), we determined the particle motion and direction of propagation of waves crossing the array. These were surface waves, with low phase velocity and almost entirely horizontal particle motion. The interesting result was that these waves were not coming from the direction of the earthquake epicenter (indicated by the bold arrows in the summary figure to the right). Instead, different packets of waves came from different, primarily westerly, directions (thinner arrows). Our conclusion is that these surface waves were generated at the edges of the sedimentary basin (the edges of the Lake Zone). Anelastic attenuation within the basin is extreme, so little energy can propagate all the way across the basin from the east. However, Mexico City, on the western edge of the basin, is shaken by an interference between a number of locally edge-generated surface waves. This interference may be expected to vary when the basin edge is illuminated by waves from earthquakes at different directions. Thus, to predict ground motion in Mexico City due to some future earthquake, we must model the 3-D response of the sedimentary basin to any incident wavefield. | ||
| To model 3-D wave propagation in a sedimentary basin like the Valley of Mexico, we are using the frequency-domain Boundary Element Method (BEM). Unlike finite difference or finite element approaches in which the entire 3-D volume is discretized, in BEM only the boundary separating the sedimentary basin from the underlying bedrock is discretized. Wave propagation from point to point on the boundary and from the boundary to the surface is computed using a propagator matrix approach we’ve been using for years. This re-duces the numerical problem by one dimension. However, for realistic structures like the Valley of Mexico, BEM still involves the solution of a huge matrix equation. We’ve tried iterative sparse matrix solution methods on supercomputers at Cornell, San Diego and Michigan, but the solution converges slowly or not at all. Cur-rently we are developing a fast-multipole method (FMM) coupled with the BEM. | ![]() |
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| This involves computing
spatial derivatives of the propagator matrix functions, but again, we’re
pretty good at that. This should reduce the matrix problem size so that
it can be solved on today’s computers. Meanwhile, we are limited to smaller
basins and lower frequencies. An example, from Kyoung-Tae Kim’s dissertation,
is shown to the right. These are synthetic ground motions for Caracas, Venezuela,
computed for incident waves appropriate for the 1967 Ca-racas earthquake.
You are looking at a N-S line of stations for a wave propagating toward
the East. Most of what you see are the incident waves which arrive simultaneously
at each station. Over the basin, however, which is between the white traces,
small waves may be seen to propagate back and forth. These edge-generated
waves are triggered by each incident wave. While
programming and testing the FMM-BEM method, we are trying to construct a
3-D subsurface model for the Valley of Mexico. This is not a simple process,
but our colleagues at UNAM in Mexico City are very helpful. I hope that
by the next newsletter I will be able to tell you how those edge-generated
surface waves form and propagate, and to produce figures or animations of
the surface ground motion in Mexico City for any number of scenario earthquakes.
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by Robert V. Demicco |
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For
the past ten years or so, my research has focused upon applications of
fuzzy logic in geology. Yes, I know what those of you who remember me
are thinking, “when wasn’t his logic fuzzy?” You may also re-member the
2000 presidential debates when Gore and Bush accused each other of “fuzzy
math”. Well, I am here to set the record straight. There is a sophisticated
body of engineering literature developed by systems sci-entists that is
based on what has come to be known as fuzzy logic. Fuzzy logic was initially
developed for ro-botic control and, if you have recently bought an appliance
or automobile advertised as being “intelligent” or “smart”, you are the
proud owner of a silicon chip with a built in fuzzy controller. |
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Dick
Andrus Jeffrey
Barker Robert
V. Demicco Steve
Dickman Joe
Graney Dave
Jenkins Peter
Knuepfer Tim Lowenstein See Chair's Letter. Bill
MacDonald Sid
Mitra Dick
Naslund Karen
Salvage Jim
Sorauf Francis
Wu |
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GSA Alumni Reception An alumni reception is tentatively planned for the Annual GSA Meeting in Denver, Nov. 7-10. If you are attending GSA this year, please plan to visit with your fellow graduates!
Photo by David Tuttle |
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Happenings Around the Department Graduate Student Excellence Awards Please join with me in congratulating
the following two graduate students for receiving Graduate Student Excellence
Awards from the University this year. They are: Recent Masters Theses and Doctoral Dissertations Ian A. Lunt
(PhD, 2002) A three-dimensional, quantitative depositional model
of gravelly braided river sediments : with special reference to the spatial
distribution of porosity and permeability. |
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Graduate
in the News
Hats off to Chris Neuzil (1971) who is now Chair of the Hydrogeology Division of the Geological Society of America. |
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Welcome
!!! Michael Hubenthal Education Specialist for IRIS (Incorporated Research Institutions for Seismology). Working from an office in our building, Michael uses internet videoconferencing to "tele-commute" with IRIS headquarters in Washington, DC, developing and disseminating educational materials making use of IRIS' global seismic data. In addition to obvious collaborations with Francis Wu, Alan Jones and Jeff Barker, all members of the department should benefit from Michael's expertise and enthusiasm. |
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| Richard
Andrus, Faculty Graham Baird, 2001 Kathleen Benison, 1993 Christopher Benison, 1994 Andrew & Mary Bobst, 1999 Jennifer Candela, 1993 Francine Cohen, 1985 Carin Criscitello, Staff Brendan Curran, 1983 |
Alex Czuhanich, 1988 |
Nancy
Katyl, 1992 Cynthia & Matthew Kawa, 1998 Randy & Adriana Kuehnel, 1986 Thomas Leshendok, 1972 Maureen Leshendok, 1970 Jianren Li, 1996 Chris Marone, 1981 Scott Muggleton, 2002 Kim Kucharski Muller, 1979 |
John
Richard Nelson, 1984 Angela Paolucci, 2001 Karen Salvage, Faculty Kyra Schnauber, Staff Jason Sents, 1998 Michael Teetsel, 1981 Qingjun Yao, 1994 Michael James Zaleha, 1994 |
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Please Join our Website Alumni List Jeff Barker Webmaster Our alumni webpage (http://geology.binghamton.edu/alumni.html) currently lists more than 180 of our alumni, with email addresses, web URLs and short updates. We would love to add you to that list, but privacy regulations prohibit this without your consent. The easiest way to join this wonderful group is to fill out the web form linked from our alumni webpage. You can also email information directly to Jeff Barker (barker@geol.binghamton.edu) or send regular mail to the Department. We hope that this on-line alumni list can serve as a resource for you. It is already a valuable resource for our current students, who wonder what one can do with a degree in Geology, or who need contacts or advice in finding that first job. We will also use the email addresses to keep you informed of events and activities like the Bartle lectures and field trips, or the (roughly) annual GSA reception. |
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The Department gratefully acknowledges the following individuals who have contibuted to Departmental accounts over the past year. |
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Richard Andrus, Faculty |
Eric
J. Daniels, 1985 Donald DePaolo, 1973 Aram Derewetzky, 1983 Martha Dunn, 1980 Timothy Eriksen, 2001 Shaun Fisher, 1982 William Frederick, 1987 Bruce Gaither, 1975 Bruce Alan Geller, 1981 Sandra Giragosian, 1959 Christine Iannello Gonzalez, 1998 Kenneth Helm, 1982 Eric Hetland, 1999 Laura Howe, 1997 Peter Jacobson, 1978 Marc Jacofsky, 1999 David Jenkins, Faculty Suzanne Karajaberlian, 2001 Nancy Katyl, 1992 |
Cynthia & Matthew
Kawa,1998 |
Karen
Salvage, Faculty Kyra Schnauber, Staff Karen Seitz, 1983 Jason Sents, 1998 Carl Stock, 1974 Robert Sudaley, 1982 Anthony Joseph Tabone, 1992 Michael Teetsel, 1981 Donna Weidemann, 1981 Gary Weinreb, 1983 Ann Sears Wilke, 1984 Walter Frederick Wintsch, 1982 Lilin Xie, 1995 Qingjun Yao, 1994 Donald Young, 1979 Michael James Zaleha, 1994 |
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Please note that this list was compiled from information provided by the Binghamton Foundation based on their records of January 2003 through December 2003. We sincerely apologize for any errors, omissions, or inaccuracies! |
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Kent
Johnsons premature death was a surprise and an especially heavy
blow to those of us in the Department involved with Guatemalan geology.
Kent was perhaps the last of the Viet Nam veterans among our graduate
students. He came to Binghamton excited about the prospect of working
in Guatemala, which required two seasons of about three months each in
the field working under difficult conditions, and functioning in a rural
area where English was unknown. He plunged into his work with a characteristic
enthusiasm familiar to all of us in the Department at that time. Working
at the same time as Peter Muller, and in adjacent quadrangles, the two
had many arduous adventures and exciting finds, several of which they
dragged their aging adviser to see and marvel at. Kents neatest
find was that of recently offset alluvial fans along an active branch
of the Motagua Fault system, in which he demonstrated maximum offsets
of nearly a kilometer diminishing progressively to the west. Kent was
one of the Departments last classical geologists, whose
research spanned geomorphology, metamorphic petrology, structural geology,
and a host of other sub disciplines.
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Last modified on 4/22/04 (adh)