Sign In

[X] Login to ...

Home > Academics > Divisions > Mathematics and the Natural Sciences > School of Earth and Environmental Sciences > People > Faculty Research
People


 

Stephen Pekar

Associate Professor
Stratigraphy

Science Building, Room D204
Phone: 718-997-3305
Stephen.Pekar@qc.cuny.edu



View Resume

Research Interests
 
I am a geologist with research interests that encompass a wide variety of problems related to Cenozoic climatic change. To tackle these problems, I develop sedimentological, microfossil, and geochemical data obtained from cores that were taken from near-shore to the deep-sea. These are used to extract climatic, oceanographic, and global sea-level signals at the decadal- to million-year scale. My research can be broadly divided into three groups.
 
The first group focuses on developing a better understanding of the Cenozoic climatic history of Antarctica. To this end, I am a member of the ANDRILL (ANtarctic DRILLing) Program, which "is a multinational initiative that aims to recover stratigraphic core records for interpreting Antarctic's climatic, glacial, and tectonic history for the past 50 Ma". In the 2005 and 2007, I was part of the Southern McMurdo Sound Drilling Project, which first collected multichannel seismic data to image sediments below the sea floor and then in the second year, recovered sedimentary cores up to 2 to 20 million years old. I have been working on the stratigraphy of late Early Miocene (17.9-16.1 Ma) portion of the core.
 
In 2008, I was the lead Principal Investigator of the Offshore New Harbor Project, which imaged sedimentary archives below the sea floor 10-30 km off the coast of East Antarctica using multi channel seismic data. The expedition camp, which was located on 20 foot thick sea ice, was located over 70 km from the McMurdo Station.  The goal of the expedition is to image sediments that were deposited when Antarctica was mainly ice free (50-35 million years ago).
 
Most recently, I was the foraminiferal paleontologist for the Integrated Ocean Drilling Program Expedition 318: Wilkes Land, Antarctica.  This expedition collected sedimentary cores up to 1,000 meters below the sea floor off the coast of Antarctica, recovering sediments up to 53 million years old.  Currently, I am working on three projects.
1) Developing a high-resolution sedimentological study using IRD’s (ice rafted debris) to evaluate not only the extent of the ice during the start of the icehouse world (34-24 Ma) but also using radiometric ages of the minerals track where the icebergs originated and thereby which ice streams were reaching the coastline;
2) Developing high-resolution (3.5 ky) stable isotope (carbon and oxygen) and Mg/ Ca ratio records from both planktonic from Site U1361 for the late Miocene (11.5-11.0 Ma), a time of potential warming in Antarctica when the ice sheet and climate was supposively cold and stable.
3) Developing ultra-high resolution (5 year) stable isotope records from both benthic and planktonic foraminifers for the Holocene from Site U1357, which is located 20 km off the coast of Antarctica. This is a collaborative effort with Rob Dunbar of Stanford University.  
 
The second group combines projects that use a new method to constrain global sea-level amplitudes that I developed and then implemented for pre-Pleistocene records. This involves an integrated approach using lithofacies, age control, foraminiferal biofacies, and two-dimensional backstripping. A third set of projects are aimed at gaining greater insights into paleoceanographic and climatic changes during important warm periods in Earth's history: the early Miocene (21-16 Ma) and late Paleocene (59-55 Ma). These projects use stable isotopes and trace metals to reconstruct climatic and paleoceanographic changes.
 
Teaching Philosophy and Interests

My teaching objectives are based on my training and experience as a primary, secondary, and university level educator, the needs of the students, and my own interest in the earth sciences. In instructing introductory geology students, I have three main objectives:

  • To spark students' curiosity and excitement about the world around them. For most students, an introductory geology course is their first experience in learning and exploring science. This provides me as an educator with the opportunity to motivate students to look beyond their immediate surroundings (to teach what is outside the four walls), with the result that they become more interested, concerned, and amazed at the diversity of biological and physical environments on and within the planet. I do this by creating a positive, student-centered environment in the class (as well as outside the class, e.g., field trips).
  • To teach at an introductory level the methodologies of modern contemporary science. This is critical in ensuring that the populace has a basic understanding of science in deciding public policy.
  • To integrate up to date science and societally relevant topics into the curriculum (bringing geology "to life"). I hope to show students that entering the field of geology can be a rewarding experience, which can contribute to society.

For upper level undergraduate classes, such as stratigraphy, I have two main goals.

  • To promote and encourage the use of the scientific method and the method of the multiple working hypotheses.
  • To frame any geology course using a larger multi disciplinary approach to the earth sciences. This gives them a broader perspective and experience of the wide array of geological applications that can serve them in their future careers.
Courses taught
 
Undergraduate
  • GEOL101 Physical Geology
  • GEOL102 Historical Geology
  • GEOL202 Earth Materials II
  • GEOL213 Sedimentology and Stratigraphy
  • GEOL239 Evolution of Ecosystems

Graduate

  • GEOL502 Earth History and the Fossil Record


Publications

Wilson, G.S., Pekar, S.F., Passchier, S., 2009, Oligocene-Miocene boundary: In Florindo, F., and Siegert, M., Antarctic Climate Evolution/Antarctic History, Elsevier B.V..

Pekar, S.F., 2008, When did the icehouse cometh?: in News and Views in Nature, 455:602-603.

Pekar, S.F., Christie-Blick, N., 2008, Resolving apparent conflicts between oceanographic and Antarctic climate records and evidence for a decrease in pCO2 during the Oligocene through early Miocene (34-16 Ma): Palaeogeography, Palaeoclimatology, Palaeoecology, 260/1-2 p. 41-49.

Pekar, S. F., DeConto, R.M., 2006, High-Resolution Ice-Volume Estimates for the Early Miocene: Evidence for a Dynamic Ice Sheet in Antarctica, Palaeogeography, Palaeoclimatology, Palaeoecology, v. 231, p. 101-109.

Pekar, S.F., DeConto, R.M., Harwood, D.M., 2006, Resolving a late Oligocene conundrum: deep-sea warming versus Antarctic glaciation: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 231, p. 29-40.

Pekar, S. F., Hucks, A., Fuller, M., and Li, S., 2005, Glacioeustatic changes in the early and middle Eocene (51-42 Ma) greenhouse world based on shallow-water stratigraphy from ODP Leg 189 Site 1171 and oxygen isotope records: Geological Society of America Bulletin, 117:1081-1093.

Pekar, S. F., Christie-Blick, N., Miller, K. G., and Kominz, M. A., 2003, Evaluating factors controlling stratigraphic architecture at passive continental margins: Oligocene sedimentation in New Jersey: Journal of Sedimentary Research, 73:227-245. (Outstanding Journal Paper in the Journal of Sedimentary Research for 2003).

 


 
 

 Faculty Listing

 
     



Queens College, CUNY| 65-30 Kissena Blvd.| Queens, NY 11367-1597| Phone: (718) 997-5000 Copyright © 2004-
Queens College is CUNY