Tag Archive for Varekamp

Lefkowitz ’12, Thomas, Varekamp Co-Author Chapter On Volcanic Lakes

Based on the senior thesis of Jared Lefkowitz ’12, “A Tale of Two Lakes: The Newberry Volcano Twin Crater Lakes, Oregon, USA,” was published online, Nov. 25, by the Geological Society of London, U.K, as part of the volume, Geochemistry and Geophysics of Active Volcanic Lakes. The study is co-authored by Lefkowitz; Ellen Thomas, research professor in earth and environmental science; and Johan Varekamp, the Harold T. Stearns Professor in Earth Science. Varekamp also is professor of environmental science, adjunct professor in Latin American studies, and chair of the Geological Society of America’s Limnogeology Division. Thomas also is the University Professor in the College of Integrates Sciences.

The chapter examines the complex ecosystems of Newberry Volcano’s two small crater lakes, East Lake and Paulina Lake, which are of interest to scientists because of the presence of highly toxic components and the signs gas-charging in East Lake. “These factors present natural hazards, which may change when new volcanic activity is initiated,” Varekamp explained. The presence of nearby “seismic triggers or disrupted lake stratification gives scientists a situation to monitor, as these factors can cause sudden intense CO2 degassing in the very different chemistries and gas contents of the two lakes.”

The authors’ abstract is online here.

Additionally, Varekamp contributed papers on Taal Lake in the Philippines and on the Copahue Volcano crater lake in Argentina. Both of these chapters will be published in the same volume in the upcoming weeks.

Paper on Guilford, Conn.’s Sea Level by Varekamp, Thomas, 2 Alumnae Receives 93 Citations

A research paper co-authored in 1995 by Johan Varekamp, the Harold T. Stearns Professor of Earth Science; Ellen Thomas, research professor of earth and environmental science; and Wesleyan alumnae Koren Nydick ’95 and Alyson Bidwell ’95 has returned to the spotlight.

The paper, “A Sea-level Rise Curve from Guilford, Connecticut, USA,” originally published in Marine Geology, was cited last month in another paper on sea-level rise in the Proceedings of the National Academy of Sciences of the United States.

Professor Varekamp admits that the “paper has done remarkably well, with 93 citations, not bad at all for a senior thesis-based article. The inclusion in this PNAS study is the icing on the cake.”

The paper developed from Nydick and Bidwell’s senior thesis work in salt marshes in nearby Guilford, Conn. As a testament to the quality of this work, a group of scientists from Boston University, Yale and Rutgers reproduced Nydick’s study two years ago with additional resources and found an identical sea level rise curve.

After earning her PhD and pursuing a post-doctoral career in ecology, Nydick now works as the science coordinator for Sequoia and Kings Canyon National Parks. Incidentally, a Smithsonian scientist funded by NASA recently contacted Nydick to inquire about the carbon core data from her thesis study for a wetlands carbon storage project.

“I am proud to note that some of my former students who are now professors or practicing scientists in their own right, have their undergraduate thesis articles among their most cited papers,” Varekamp said.

Varekamp Leads Invited Talk at Geophysical Union Meeting

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Johan “Joop” Varekamp

Johan “Joop” Varekamp, the Howard T. Stearns Professor in Earth Science, led an invited talk at the American Geophysical Union (AGU) meeting in San Francisco, Dec. 2015.

The earth and space science community participated in discussions of emerging trends and the latest research. The session, which was co-authored by former Wesleyan E&ES graduate student Lauren Camfield, focused on the 2012 eruption of the Copahue volcano in Argentina.

Due to the success of the invited talk on Volcanic Hydrothermal Systems, Varekamp will be a co-editor for a special issue of a journal based on that session. As part of his role as chair-elect of the Committee on Geology and Public Policy of the Geological Society of America (GSA), he will be interviewing five candidates in Washington D.C. for the position of congressional fellow.

Varekamp, Gilmore Co-Author Articles on Argentina’s Copahue Volcano

Joop Varekamp, the Harold T. Stearns Professor of Earth Science, professor of earth and environmental sciences, and Marty Gilmore, the George I. Seney Professor of Geology, professor and chair of professor of earth and environmental sciences, are the co-authors of two book chapters published in Copahue Volcano (Springer Publishers, September 2015)

Copahue Volcano is part of Springer Publishers’ “Active Volcanos of the World” series. Varekamp is the lead author on a chapter with Jim Zareski MA‘14 and Lauren Camfield MA’15. Gilmore and Tristan Kading MA’11 are co-authors with Varekamp on another chapter dealing with terrestrial environments as analogs for Mars. A third chapter, on acid fluids, was written by Varekamp with an Argentinian collaborator. 

Since 1997, Varekamp has worked with Wesleyan undergraduate and graduate students almost every year at Copahue Volcano in Argentina. This project is reaching its closing stages, and has led to 10 peer reviewed published articles, most co-authored with students, four book chapters, six MA theses, and eight senior theses. All these students have subsequently obtained higher degrees in E&ES fields and are currently employed in the broad field of geochemistry and/or volcanology. Varekamp is now focussing his studies on the Newberry volcano in Oregon.

Varekamp Elected Chair of Geology, Public Policy Committee

Joop Varekamp

Joop Varekamp

Johan “Joop” Varekamp, the Harold T. Stearns Professor of Earth Science, professor of earth and environmental sciences, was elected to be chair of the Geology and Public Policy Committee (GPPC) of the Geological Society of America (GSA). The group prepares position statements for GSA (e.g., on fracking, climate change). Varekamp has already made six congressional visits in March, visiting the offices of Senators Richard Blumenthal, Elizabeth Warren, Ed Markey and Representative Rosa DeLauro. He does similar work as chairman of the board of the Connecticut Fund for the Environment / Save the Sound.

Varekamp also was elected to be the chair of the LimnoGeology (‘lakes’) division of GSA for the next two years, which involves organizing conferences and sessions at annual GSA meetings, and editing special volumes on lakes.

In addition, Varekamp received funding through the Keck Geology Consortium for a research project on the two crater lakes of Newberry volcano in Oregon. Varekamp will visit the lakes this summer with a group of student researchers from Wesleyan, Amherst, Colgate and Smith College.

Varekamp Authors 2 Chapters in Volcanic Lakes Book

Volcanic Lakes. (Image courtesy of Springer Science+Business Media)

Volcanic Lakes. (Image courtesy of Springer Science+Business Media)

Johan “Joop” Varekamp, the Harold T. Stearns Professor of Earth Science, professor of earth and environmental sciences, is the author of two chapters in Volcanic Lakes, published by Springer Science+Business Media, 2015. He worked on the chapters during his sabbatical in Bristol, U.K., in 2013.

Varekamp’s chapters are titled “The Chemical Composition and Evolution of Volcanic Lakes” and “Volcanic Lakes.” Five other authors also contributed to the “Volcanic Lakes” chapter.

Volcanic lakes are natural features on the planet. The changing water compositions and colors of these lakes over time provide insights into the volcanic, hydrothermal and degassing processes of the underlying volcano.

This book aims to give an overview on the present state of volcanic lake research, covering topics such as volcano monitoring; the chemistry, dynamics and degassing of acidic crater lakes; mass-energy-chemical-isotopic balance approaches; limnology and degassing of Nyos-type lakes; the impact on the human and natural environment; the eruption products and impact of crater lake breaching eruptions; numerical modeling of gas clouds and lake eruptions; thermo-hydro-mechanical and deformation modeling; CO2 fluxes from lakes; volcanic lakes observed from space; biological activity; continuous monitoring techniques, and other aspects.

Studies by Varekamp, Thomas Published in Paleoceanography

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Joop Varekamp

Ellen Thomas

Ellen Thomas

Wesleyan faculty Joop Varekamp and Ellen Thomas are among the authors of a paper on rates of sea-level rise along the eastern U.S. seaboard titled “Late Holocene sea level variability and Atlantic Meridional Overturning Circulation,” published in the journal Paleoceanography, Volume 29, Issue 8, pages 765–777 in August 2014. Varekamp is the Harold T. Stearns Professor of Earth Science, professor of earth and environmental sciences and professor of environmental studies. Thomas is research professor of earth and environmental sciences at Wesleyan, and also a senior research scientist in geology and geophysics at Yale University.

Ellen Thomas discovered that microfossils, such as this  foraminifera fossil, reveal that warm oceans had less oxygen.

Ellen Thomas discovered that microfossils, such as this foraminifera fossil, reveal that warm oceans had less oxygen.

Pre-20th century sea level variability remains poorly understood due to limits of tide gauge records, low temporal resolution of tidal marsh records, and regional anomalies caused by dynamic ocean processes, notably multidecadal changes in Atlantic Meridional Overturning Circulation (AMOC). In the study, Varekamp and Thomas examined sea level and circulation variability along the eastern United States over the last 2,000 years, using a sea level curve constructed from proxy sea surface temperature records from Chesapeake Bay, and 20th century sea level-sea surface temperature relations derived from tide gauges and instrumental sea surface temperatures.

Thomas also is a co-author of a paper titled ‘I/Ca evidence for upper ocean deoxygenation during the PETM‘ published in the Paleoceanography, October 2014.

In this paper, Thomas suggests that the Paleocene-Eocene Thermal Maximum (PETM), a potential analog for present and future global warming, may help in such forecasting future deoxygenation and its effects on oceanic biota. Forecasting the geographical and bathymetric extent,

Varekamp, Thomas Author Chapters on Long Island Sound Reference Volume

Joop Varekamp and Ellen Thomas

Joop Varekamp and Ellen Thomas co-authored chapters in this new book on the Long Island Sound.

Joop Varekamp and Ellen Thomas are the authors of three chapters included in a reference volume for Long Island Sound. The book, Long Island Sound: Prospects for the Urban Sea, is published by Springer in 2013. Varekamp is the Harold T. Stearns Professor of Earth Science, professor of earth and environmental sciences, professor of environmental studies. Thomas is research professor of earth and environmental sciences.

Varekamp co-authored a chapter titled “Metals, Organic Compounds and Nutrients in Long Island Sound: Sources, Magnitudes, Trends and Impacts,” and another chapter titled “The Physical Oceanography of Long Island Sound.” Thomas co-authored a chapter titled “Biology and Ecology of the Long Island Sound.”

Varekamp and Thomas worked on the book for about six years.  The last comprehensive Long Island Sound book was published in the early 1970s.

“We hope that it will be the reference volume for Long Island Sound for some decades to come,” Varekamp said.

Varekamp, Students Study Volcanic Products, Waters in Argentina

Ellen Alexander '14, Professor Joop Varekamp and graduate student Lauren Camfield in Argentina.

Ellen Alexander ’14, Professor Joop Varekamp and graduate student Lauren Camfield in Argentina.

Ellen Alexander ’14, Professor Joop Varekamp and graduate student Lauren Camfield recently returned from Argentina where they studied the eruptive products of the Copahue volcano March 7-March 19.

Varekamp, the Harold T. Stearns Professor of Earth Science, professor of environmental studies, has studied the volcano since 1997. It erupted in 2000 and again in December 2012.

“Many Wesleyan students have done their senior theses and grad theses on Copahue. It’s exciting stuff for us volcanology types,” Varekamp said.

Camfield sampled the products of the most recent eruption of Copahue, which included ash, pumice and volcanic bombs. She will analyze her samples at Wesleyan for major and trace elements on a X-ray fluorescence machine and analyze any melt inclusions at the American Museum of Natural History in New York on an electron microprobe.

“This information can give us insight on what is happening in the magma chamber of the volcano as well as depth of crystallization of minerals,” Camfield said.

Wesleyan Weather Station Tracks Hurricane Sandy’s Low Air Pressure

A graph based on data collected by the Wesleyan Weather Station shows a drop in barometric pressure during the passing of Hurricane Sandy.

A graph based on data collected by the Wesleyan Weather Station shows a drop in barometric pressure during the passing of Hurricane Sandy.

The Wesleyan Weather Station recorded a strong drop in local air pressure during Hurricane Sandy on Oct. 29. According to the weather report, the local sea-level barometric pressure was a normal 760 mmHg (millimeters of Mercury) on Oct. 28. When Hurricane Sandy passed through Wesleyan’s campus on Oct. 29, the pressure dropped to a low of 733 mmHg during the storm’s peak.

“Low pressure generally indicates stormy conditions whereas high pressure is associated with fair weather,” explains Johan “Joop” Varekamp, the Harold T. Stearns Professor of Earth Science. “We tend to only see the barometer drop this low in the event of extreme weather.”

The Wesleyan Weather Station also measures the wind speed and direction, and displays graphically changes in temperature and barometric pressure over a seven-day period. During the storm, maximum wind speeds were recorded Sunday around midnight.

The Wesleyan Weather Station was established with a Teaching Innovation Grant from President Michael Roth, and is extensively used in Varekamp’s Global Climate Change class to calculate variations in atmospheric CO2 build-up during day-night cycles that vary with temperature. The station is maintained by Joel LaBella, facilities manager for the Earth and Environmental Sciences Department, Information Technology Services and Varekamp.

Thesis Research: Ocean Fish Consumption, Not Volcanoes, Cause High Mercury Levels in Costa Rica

Audrey Haynes '12 stands on the rim of the Turrialba volcano in Costa Rica. When she tested samples of human hair from 53 residents in the area, she discovered high levels of mercury in more than half of the samples.

Audrey Haynes ’12 stands on the rim of the Turrialba volcano in Costa Rica. When she tested samples of human hair from 53 residents in the area, she discovered high levels of mercury in more than half of the samples.

(Story contributed by Jim H. Smith)

Senior thesis research conducted last spring by Audrey Haynes ’12 at Costa Rica’s National University, under the tutorship of Johan “Joop” Varekamp, has shown that many residents of the Central American nation have levels of mercury in their hair that far exceed those recommended by the U.S. Environmental Protection Agency. Varekamp, whose student made the discovery as part of a broad evaluation of environmental mercury in Costa Rica, says the elevated mercury levels are probably a consequence of over-consumption of large ocean fish, not exposure to mercury in the air emitted by volcanoes, as a controversial 2011 study suggested.

The research was done in collaboration with Maria del Mar Martinez of the volcanology and seismic monitoring center (OVSICORI/UNA).

Varekamp, the Harold T. Stearns Professor of Earth Science, and his student were invited last spring to test Costa Rica’s mercury levels because research conducted by another team of scientists had found levels of mercury in Costa Rican air that were dramatically higher than those documented anywhere else in the world. While the average environmental mercury concentrations worldwide are in the neighborhood of two or three nanograms (billionths of a gram) per cubic meter of air, the 2011 study reported extraordinarily high concentrations of 600-800 nanograms Hg per cubic meter.

“This was puzzling because many small and remote countries that are less industrialized, like Costa Rica, report modest levels of airborne mercury from coal-fired power plants. Costa Rica doesn’t have any coal fired power plants, though, nor does it have any major mercury-emitting industries,” Varekamp explains.

Varekamp, Ostfeld Present Papers at National Conference

Professor Johan Varekamp and former graduate student Tristan Kading studied how a volcano eruption in 2000 affected the chemical makeup of Lake Caviahue in Argentina. Varekamp presented the study at a recent Geological Society of America meeting.

Professor Johan Varekamp made two presentations on a chemically-altered lake and urban pollution during a recent Geological Society of America meeting. (Photo by Olivia Drake)

Six Wesleyan researchers, including a graduate student, were authors or co-authors of papers chosen for presentation at this year’s annual meeting of the Geological Society of America (GSA) in Minneapolis, Minn., Oct. 9-12. It is the largest annual meeting of the preeminent scientific association in the geologic and earth science fields.

Johan Varekamp, Harold T. Stearns Professor of Earth Sciences, professor of earth and environmental sciences, presented two papers. The first, “Wethersfield Cove, Hartford, Conn. – A 300 Year Urban Pollution Record,” detailed a study of the sedimentary record of the cove, which revealed unusually high levels of Mercury. The cove, which had been surround by economic activity since colonial times, showed sedimentary mercury levels as high as 3,000 parts per billion.

The study has become the subject of a front-page feature in The Hartford Courant featuring Varekamp and three graduate students from his Graduate of Liberal Studies (GLSP) class, Kristen Amore, Julia Rowny and Luis Rodriguez, assistant store manager at Cardinal Technologies, who joined Varekamp to do ongoing samplings of the cove.

Varekamp also was asked to present his paper, Lake Caviahue (Argentina) Nearing Schwertmannite Saturation, which charted the chemistry-altering changes in the lake since the eruption of the Copahue volcano in 2000.

The paper was co-authored by Varekamp’s former graduate student Tristan Kading MA ’10, who is now a Ph.D. candidate at the Woods Hole Oceanographic Institute. Kading did much of his master’s study on Lake Caviahue.

The volcano’s runoff into Lake Caviahue has raised the lake’s acidity over the last 11 years creating a near saturation of the mineral schwertmannite, which has given the water a yellow-brown color.