Tag Archive for Earth and Environmental Sciences

NASA Funds Study of Gilmore’s Venus Mission Concept

Martha Gilmore

Martha Gilmore, the George I. Seney Professor of Geology, professor of earth and environmental sciences, believes we have a lot to learn from studying Venus—yet the United States has not sent a mission to the Earth-sized planet since the early 1990s. That’s why Gilmore has proposed a major flagship mission concept study to assess whether Venus was ever a habitable planet by looking at its rocks and atmosphere.

In October, NASA agreed to fund the planetary mission concept on Venus submitted by Gilmore, a planetary geologist, and colleagues at several other institutions, who come from varied disciplines. Gilmore, who is the principal investigator, said NASA received 54 proposals and selected 10 to feed into the next Planetary Decadal Survey. Theirs was the only proposal on Venus to receive funding.

In 2020, the National Academy of Science will convene a panel of scientists and engineers to determine the scientific priorities for Planetary Science over the period 2023–2032. This Planetary Decadal Survey is conducted every 10 years and is tasked with recommending a portfolio of missions to NASA. The mission concepts that were funded will be developed for consideration by the Decadal Survey. In the coming months, Gilmore will be meeting and communicating regularly with her science team and conducting mission design runs at NASA’s Goddard Space Flight Center in Maryland. Final reports are due to the Decadal Survey in June 2020, and will describe mission architecture, cost, and how the mission will address the scientific priorities of the Decadal Survey and NASA.

Gilmore’s expertise is on the surface morphology and composition of Venus, Mars, and Earth, and her PhD focused on Venus during the United States’ Magellan mission. She explained that all three planets are rocky, and there is evidence that they all had oceans early in solar system history. Scientists believe that Mars’s ocean dried up first—within about one billion years—and that Venus’s ocean may have lasted for two or three billion years.

“Thus, for most of solar system history, there were two Earth-sized planets with oceans,” said Gilmore. “Was Venus habitable like the Earth and if so, what changed?”

“Bomb Cyclone” Strikes Campus on Oct. 17, Causing Extremely Low Pressure, High Winds

weather station

The Wesleyan University Weather Station measures wind speed, barometric pressure, air temperature, relative humidity, and solar irradiance.

On Oct. 17, the Wesleyan Weather Station recorded a dramatic drop in atmospheric (barometric) pressure—a drop so severe it compared to one from Hurricane Sandy in November 2012.

Between 2 a.m. on Oct. 16 and 2 a.m. on Oct. 17, the pressure dropped from 1020 to 980 millibars, resulting in what meteorologists refer to as bombogenesis or a “bomb cyclone.” Bomb cyclones are defined by a drop of more than 24 millibars of pressure over less than 24 hours, and here, the pressure dropped 40 millibars.

During Hurricane Sandy the pressure also dropped to 980 millibars.

“We’ve looked through the last three years of data collected by the Wesleyan Weather Station, and no other event over that time period is more dramatic than this one,” said Dana Royer, professor of earth and environmental sciences. “This clearly shows that the bomb cyclone this month was indeed unusual.”

In Hartford, Conn., the pressure minimum (~980 millibars, similar to the pressure the Wesleyan Weather Station recorded) tied the all-time record for the month of October.

The bomb cyclone also affected wind speed. Between 1 and 2 a.m. on Oct. 17, wind rapidly increased from 0 to 34 mph and fluctuated between 5 and 25 mph over the next 24 hours.

The Wesleyan Weather Station was established with a Teaching Innovation Grant from President Michael Roth and Johan “Joop” Varekamp, the Harold T. Stearns Professor of Earth Science. The station and weather “dashboard” is maintained by Joel LaBella, facilities manager for the Earth and Environmental Sciences Department.

bomb cyclone

The Wesleyan Weather Station recorded the dramatic drop in atmospheric pressure on Oct. 17. This graph shows the average air pressure from the last 30 days.

bomb cyclone

During the bomb cyclone, the Wesleyan Weather Station recorded the drastic fall in atmospheric pressure and the rapid rise in wind speed.

O’Connell in The Conversation: How Deep is the Ocean?

Wesleyan faculty frequently publish articles based on their scholarship in The Conversation US, a nonprofit news organization with the tagline “Academic rigor, journalistic flair.” Professor of Earth and Environmental Sciences Suzanne O’Connell has written a new article for The Conversation’s “Curious Kids” series answering the question “How deep is the ocean?” The article is based on her research studying the sea floor.

Curious Kids: How deep is the ocean?

The remotely operated vehicle Deep Discoverer captures images of a newly discovered hydrothermal vent field in the western Pacific. NOAA

The remotely operated vehicle Deep Discoverer captures images of a newly discovered hydrothermal vent field in the western Pacific. (NOAA)

Explorers started making navigation charts showing how wide the ocean was more than 500 years ago. But it’s much harder to calculate how deep it is.

If you wanted to measure the depth of a pool or lake, you could tie a weight to a string, lower it to the bottom, then pull it up and measure the wet part of the string. In the ocean you would need a rope thousands of feet long.

In 1872 the HMS Challenger, a British Navy ship, set sail to learn about the ocean, including its depth. It carried 181 miles (291 kilometers) of rope.

During their four-year voyage, the Challenger crew collected samples of rocks, mud and animals from many different areas of the ocean. They also found one of the deepest zones, in the western Pacific, the Mariana Trench, which stretches for 1,580 miles (2,540 kilometers).

O’Connell Works with International Scientists to Collect Sediment Cores from Scotia Sea

JOIDES

The JOIDES Resolution at the pier in Punta Arenas, Chile. (Credit: Thomas Ronge & IODP)

Suzanne O'Connell

Suzanne O’Connell

As campus was winding down for spring break last semester, Professor of Earth and Environmental Sciences Suzanne O’Connell was packing her bags for a two-month expedition in the Scotia Sea, just north of the Antarctic Peninsula, to drill for marine sediment miles below the ocean waves.

On her ninth expedition since 1980, O’Connell was one of 30 international scientists working 12 hours a day, seven days a week, navigating “Iceberg Alley” aboard the JOIDES Resolution research vessel. It is the only ship in the world with coring tools powerful enough to extract both soft sediment and hard rock from the ocean floor.

At five carefully selected sites the ship stopped, and—provided the vicinity was iceberg-free—scientists lowered coring equipment through an opening in the floor of the ship to drill 0.5 to 2.5 miles down through the water and into the ocean sediment. After two hours, the equipment (which uses an action similar to that of coring an apple), would bring back the 31-foot-long core. Back on board, the cores were cut into 1.5-meter segments and then split lengthwise to reveal a layer cake of preserved mineral and organic sediment, each layer representing a snapshot of the ocean floor from a moment in geologic history.

Yang ’21 Participates in NSF-Sponsored Workshop on Antarctic History

Donglai Yang ’21 worked at the University of Arizona this summer on a project titled “Cenozoic detrital record offshore Dronning Maud Land.” His workshop concluded on July 8.

For two weeks this summer, Donglai Yang ’21 used isotope dating of rocks, minerals, and sediments from the Weddell Sea near Antarctica to determine the age of a section of Earth’s southernmost continent.

Yang, an earth and environmental sciences and physics double major, was selected as one of 10 undergraduate and graduate students from around the world to participate in the National Science Foundation–sponsored Antarctichron/Chronothon 2019 workshop held June 24 to July 8 at the University of Arizona.

The workshop introduced participants to geo- and thermochronology through some applications to the geology of Antarctica. Students learned to analyze and interpret their own samples and data in the context of their own research projects.

Yang’s study focused on the “Cenozoic detrital record offshore Dronning Maud Land,” a Norwegian territory that makes up approximately 1/6 of Antarctica. He specifically studied rock and sediment fragments that broke away from a landmass.

“These sediments were deposited around 30 million years ago, but the minerals within that layer of sediments have diverse ages,” he said. “Those minerals are scraped directly from the Antarctic bedrock by glaciers so their ages bear complicated terrestrial thermal history.”

During the workshop, Yang participated in informal lectures and discussions and learned the fundamentals of radioisotopic dating, laboratory techniques, analytical instrumentation, basics of thermochronologic modeling, and the geology of Antarctica. Core samples were provided by the International Ocean Discovery Program sediment core repository and the fellowship also was supported by Wesleyan’s College of the Environment.

Yang’s advisor, Suzanne O’Connell, professor of earth and environmental sciences, initially introduced Yang to the concept of radiometric dating in geosciences.

“I was fascinated at once,” he said. “Its current applications have far transcended its use since its advent when, about a hundred years ago, scientists finally managed to fathom the absolute age of the Earth.”

Now with a much-expanded understanding of the kinetics in multiple decay systems, questions that arise from almost every single field in earth and environmental sciences become resolvable to varying extents, Yang explained. “On top of this, our sedimentology lab reckons it a valuable opportunity to bring in some new techniques as we have rarely dealt with unstable isotopes in minerals before.”

After Yang graduates from Wesleyan, he plans on attending graduate school, conducting research in geophysics or geochemistry.

Herbst and Greenwood in The Conversation: The Tell-Tale Clue to How Meteorites Were Made

Wesleyan faculty frequently publish articles based on their scholarship in The Conversation US, a nonprofit news organization with the tagline, “Academic rigor, journalistic flair.” In a new article, John Monroe Van Vleck Professor of Astronomy Bill Herbst and Assistant Professor of Earth and Environmental Sciences James Greenwood write about the model they’ve proposed for how the most common kind of meteorites form—a mystery that has dogged scientists for decades.

The tell-tale clue to how meteorites were made, at the birth of the solar system

April 26, 1803 was an unusual day in the small town of L’Aigle in Normandy, France – it rained rocks.

Over 3,000 of them fell out of the sky. Fortunately, no one was injured. The French Academy of Sciences investigated and proclaimed, based on many eyewitness stories and the unusual look of the rocks, that they had come from space.

The Earth is pummeled with rocks incessantly as it orbits the Sun, adding around 50 tons to our planet’s mass every day. Meteorites, as these rocks are called, are easy to find in deserts and on the ice plains of Antarctica, where they stick out like a sore thumb. They can even land in backyards, treasures hidden among ordinary terrestrial rocks. Amateurs and professionals collect meteorites, and the more interesting ones make it to museums and laboratories around the world for display and study. They are also bought and sold on eBay.

Despite decades of intense study by thousands of scientists, there is no general consensus on how most meteorites formed. As an astronomer and a geologist, we have recently developed a new theory of what happened during the formation of the solar system to create these valuable relics of our past. Since planets form out of collisions of these first rocks, this is an important part of the history of the Earth.

This meteor crater in Arizona was created 50,000 years ago when an iron meteorite struck the Earth. It is about one mile across. W. Herbst, CC BY-SA

This meteor crater in Arizona was created 50,000 years ago when an iron meteorite struck the Earth. It is about one mile across. (Photo by Bill Herbst, CC BY-SA)

The mysterious chondrules

Students Study Volcanic Soil, Map Historic Footprints in Hawai’i as Part of Their Senior Capstone Projects

 Left to right: Tim Ku (faculty), Celeste Smith, Jacqueline Buskop, John Sheffer, Ryan Nelson, Sara Wallace-Lee, Kelly Lam, and Phil Resor (faculty) at a newly formed black sand beach on Hawaii. The rocks on the left solidified in 2018.

At left, Associate Professor of Earth and Environmental Sciences Tim Ku, Celeste Smith ’19, Jacqueline Buskop ’19, John Sheffer ’19, Ryan Nelson ’19, Sara Wallace-Lee ’19, Kelly Lam ’19, and Associate Professor of Earth and Environmental Sciences Phil Resor visit a newly formed black sand beach on Hawai’i. The rocks on the left solidified in 2018.

Six students majoring in earth and environmental sciences who said “aloha” to Hawai’i in January have completed their senior capstone project.

Seniors Jackie Buskop, John Sheffer, Kelly Lam, Sara Wallace-Lee, Ryan Nelson, and Celeste Smith traveled to the Big Island of Hawai’i Jan. 8-15 to conduct original, field-based research projects. They were accompanied by Associate Professors of Earth and Environmental Sciences Tim Ku and Phil Resor.

Prior to the trip, all six students enrolled in the fall semester course Senior Seminar E&ES 497, where they used the primary scientific literature to create hypothesis-driven research proposals. After collecting data in Hawai’i, the students enrolled in E&ES 498, where they analyzed and interpreted their data, and summarized their projects in journal article–style reports. On April 7, the students presented their results in short talks at the E&ES colloquium.

“Through this capstone sequence, students learn to develop and execute a research project from the initial idea through the planning, field collection, and data interpretation stages, and finally, how to synthesize this work into an illuminating presentation and written report,” Ku said. “We hope this capstone experience helps students transition to independent, professional scientists.”

Buskop, Sheffer, and Smith teamed up to work on a project titled “Inferences from 3D Modeling and Field Measurements of Human Footprints of the Ka’u Ash Desert (Kilauea, Hawai’i).”

O’Connell in The Conversation: 60 Days in Iceberg Alley, Drilling for Marine Sediment to Decipher Earth’s Climate 3M Years Ago

Wesleyan faculty frequently publish articles based on their scholarship in The Conversation US, a nonprofit news organization with the tagline, “Academic rigor, journalistic flair.” In a new article, Professor of Earth and Environmental Sciences Suzanne O’Connell writes about her work on board the JOIDES Resolution research vessel in the Scotia Sea, drilling for sediment core samples to study how much and how fast the Antarctic ice sheets melted between 2.5 to 4 million years ago, the last time atmospheric CO2 was at the same level as today. (Read more about O’Connell’s experience in this AAAS article.)

60 days in Iceberg Alley, drilling for marine sediment to decipher Earth’s climate 3 million years ago

Competition is stiff for one of the 30 scientist berths on the JOIDES Resolution research vessel. I’m one of the lucky ones, granted the opportunity to work 12-hour days, seven days a week for 60 days as part of Expedition 382 “Iceberg Alley” in the Scotia Sea, just north of the Antarctic Peninsula.

I’m a paleooceanographer. My research focuses on how Earth’s oceans and climate operated in the past; I’m especially interested in how much and how fast the Antarctic ice sheets melted between 2.5 to 4 million years ago, the last time atmospheric carbon dioxide levels were about 400 parts per million, as they are today. This work depends on collecting sediment samples from the ocean floor that were deposited during that time. These sediment layers are like a library of the Antarctic’s past environment.

The JOIDES Resolution is the only ship in the world with the drilling tools to collect both soft sediment and hard rock from the ocean – material that we recover in long cylinders called cores. No wonder researchers from all over the world, at all career stages, are excited to have traveled from India, Japan, Korea, the Netherlands, Germany, Spain, Switzerland, Brazil, China, Germany, Australia, the United Kingdom and, of course, the United States to join the expedition.

Study by Herbst, Greenwood Presents New Theory on How Meteorites Formed

A paper by John Monroe Van Vleck Professor of Astronomy William Herbst and Assistant Professor of Earth and Environmental Sciences James Greenwood will be published in the September 2019 issue of Icarus, published by Elsevier. The paper is available online.

The paper, titled “Radiative Heating Model for Chondrule and Chondrite Formation,” presents a new theory of how chondrules and chondrites (the most common meteorites) formed. It suggests a new approach to thinking about these rocks that populate the meteorite collections on Earth. It includes both theory and experiments (completed in Greenwood’s lab in Exley Science Center).

These laboratory experiments demonstrate that porphyritic olivine chondrules, the most voluminous type of chondrule, can be made using heating and cooling curves predicted by the “flyby” model. View a schematic diagram here.

“The problem of how chondrules and chondrites formed has been around for decades—more than a century, really. We cannot yet claim to have solved the problem but we have provided a new idea about the solution that passes many tests,” Herbst explained.

The basic idea, Herbst said, involves heating of small fluffy “rocks” in space as they fly past molten lava eruptions on larger asteroids, during the first few million years of the solar system’s existence.

Herbst, Greenwood, and Postdoctoral Research Associate Keniche Abe, will present this research at meetings this summer in Europe and Japan.

Varekamp Presents Papers at Volcanic Lakes Meeting in New Zealand, Receives Award

Johan (Joop) Varekamp

Joop Varekamp

Johan (Joop) Varekamp, the Harold T. Stearns Professor of Earth Science, presented three papers during the Commission on Volcanic Lakes (CVL) program held March 18-20 in Taupo, New Zealand. The papers were coauthored by Wesleyan students, graduate students, recent alumni, and faculty.

The CVL is a scientific, nonprofit organization of the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI), connecting researchers that seek to understand how volcanic lakes relate to volcanic activity and their hazards.

Varekamp, who also is the Smith Curator of Mineralogy and Petrology of the Joe Webb Peoples Museum of Natural History and professor of earth and environmental studies, is a former leader of the CVL organization. In addition to delivering a keynote address, Varekamp was named the recipient of the 2019 IAVCEI Kusakabe Award.

Fish Species Named After Professor Barry Chernoff

Bryconops chernoffi

Bryconops chernoffi

A new species of fish discovered in Brazil was recently named in honor of Wesleyan Professor Barry Chernoff.

Barry Chernoff

Scientists encountered the Bryconops chernoffi in Rio Ipixuna—a small tributary of the Rio Maicuru, which feeds into the lower Amazon River in Pará, Brazil. Samples of the fish were collected by researchers on four trips in 2014–15, and in March 2019, Zootaxa released an article describing the new species.

Chernoff, the Robert Schumann Professor of Environmental Studies, focuses his research on freshwater fishes in North America and the Neotropical region, primarily those in South America in the Amazon.

He’s also professor of earth and environmental sciences; professor of biology; chair, Environmental Studies Program; and director of the College of the Environment.

The Zootaxa announcement explains that Bryconops chernoffi’s specific epithet honors “Barry Chernoff, and is in recognition for his contributions to the taxonomy of Bryconops, as well as for ichthyology as a whole.”

Chernoff has published 89 peer-reviewed scientific works, including six books and edited volumes. He has led international teams on expeditions designed to conserve large watersheds of the world, having made more than 34 expeditions in 13 countries.

The Zootaxa abstract describes Bryconops chernoffi as differing from all its congeners “by the presence of an elongated dark patch of pigmentation immediately after the posterodorsal margin of the opercle, running vertically from the supracleithrum to the distal margin of the cleithrum (vs. absence of a similar blotch), and by a dark dorsal fin with a narrow hyaline band at middle portion of dorsal-fin rays (vs. dorsal fin hyaline or with few scattered chromatophores). It differs further from all its congeners, except B. colanegra, by the presence of a blurred black stripe at the anal fin.”

“It doesn’t really resemble my friend Barry, who in addition to being a fish scientist and environmentalist is also a guitar player and songwriter,” wrote Wesleyan President Michael Roth in a recent blog post. “And now he has fish named in his honor. A true species of Wesleyan.”

Chernoff is the third Wesleyan faculty, in recent years, to have a species named in his or her honor.

In 2010, a dinosaur from the Cretaceous Period (about 110 million years ago) was named Brontomerus mcintoshi for John S. “Jack” McIntosh, Foss Professor of Physics, Emeritus. The fossil, discovered in Utah, is marked by its large, powerful thighs, which may have been used to kick predators and travel over rough terrain. The American-British team of scientists who discovered the remains named the dinosaur for McIntosh, “a lifelong avocational paleontologist.”

Two species of benthic foraminifera are named after Ellen Thomas, the Harold T. Stearns Professor of Integrative Sciences, research professor, earth and environmental sciences; the Smith Curator of Paleontology of the Joe Webb Peoples Museum of Natural History.

Globocassidulina thomasae, discovered in the northeastern Indian Ocean, was named in 1999, and Ossaggittia thomasae, discovered in the eastern Indian Ocean, was named in 2012. They were named in honor of Ellen Thomas, “a well-known specialist on deep-sea benthic foraminifera, who was one of the first micropaleontologists to document the disappearance of Stilostomellidae and Pleurostomellidae in the Pleistocene of the North Atlantic Ocean.”

Students, Faculty, Alumni Present Research at 50th Annual Planetary Science Conference

Jeremy Brossier presented a talk titled "Radiophysical Behaviors of Venus’ Plateaus and Volcanic Rises: Updated Assessment." He also presented a poster titled "Complex Radar Emissivity Variations at Some Large Venusian Volcanoes."

At left, earth and environmental sciences postdoctoral research associate Jeremy Brossier presented a poster titled “Complex Radar Emissivity Variations at Some Large Venusian Volcanoes” during the Lunar and Planetary Science Conference in Texas.

Several Wesleyan students, faculty, and alumni attended the 50th Lunar and Planetary Science Conference (LPSC) March 18-22 in The Woodlands, Texas. Members of the Wesleyan Planetary Sciences Group presented their research on a range of planetary bodies.

This annual conference brings together international specialists in petrology, geochemistry, geophysics, geology, and astronomy to present the latest results of research in planetary science.

Earth and environmental studies major Emmy Hughes ’20 presented a poster titled “Observations of Transverse Aeolian Ridges in Digital Terrain Models” during a session on “Planetary Aeolian Processes.”

Earth and environmental science graduate student Reid Perkins MA ’19 presented a talk titled “A Reassessment of Venus’ Tessera Crater Population and Implications for Tessera Deformation” and a poster titled “Volumes and Potential Origins of Crater Dark Floor Deposits on Venus.”