PEOPLE

John A. Higgins

Professor John Higgins

Professor John Higgins' primary research interest is the evolution of the carbon cycle and the global climate system over Earth history.  One focus has been on processes that control the chemical composition of seawater, and how those processes have changed on geologic timescales.  Another is how on the chemistry of carbonate sediments is affected by processes that occur post-deposition.  These include early diagenetic recrystallization, dolomitization and hydrothermal alteration.  The tools Prof. Higgins has employed to study these include numerical models of chemical and isotopic biogeochemical cycles, as well as analysis of traditional stable isotopes of oxygen and carbon, and new isotope systems such as magnesium, calcium, and potassium.

Department/Program(s): Geosciences
Position: Active Faculty
Title: Assistant Professor
Area(s): Geochemistry
Field: Geochemistry and Paleoclimate
Office: 212 Guyot Hall
Phone: 609-258-7024

 

Anne-Sofie Crüger Ahm

Anne-Sofie C. Ahm

Anne-Sofie C. Ahm is a Carlsberg Foundation Postdoctoral Fellow working on numerical models of carbonate diagenesis and measurements of Ca, Mg, and Sr isotopes. She is intrigued by the fundamental processes that transform lithified sediments into rocks and how these processes affect the geochemical signature stored in the rock record of Earth history. In particular, she is interested in what the record of marine carbonate diagenesis - as revealed through the geochemical signature of Ca, Mg, and Sr isotopes - can tell us about ancient seawater chemistry surrounding the end-Cryogenian Marinoan glaciation. 

Department/Program(s): Geosciences
Position: Research Staff
Title: Visiting Fellow, Geosciences
Office: 210 Guyot Hall
Phone: 609-216-6060
Email: aahm@princeton.edu

 

Alliya A. Akhtar

 Alliya A. Akhtar

An appreciation of the coevolution of the Earth and its biosphere requires a focus on the integration and application of low temperature geochemistry to the paleontological and sedimentary record. Alliya Akhtar is particularly interested in studying the chemical and climatic conditions governing times of not only proliferation, but also distress of animal life. Employing various isotope systems can aid in establishing constraints on changes in climate and ocean chemistry. Coupling this with isotopic studies in modern environments will aid in better understanding the information we derive from these proxies.

Department/Program(s): Geosciences
Position: Graduate Student
Office: 209 Guyot Hall
Phone: 609-258-9836
Email: aakhtar@princeton.edu

Visitors and Former Students

GRADUATE STUDENTS
Jonathan Husson *15
Anne Gothmann *15

 

POSTDOCTORAL
Or Bialik
Blake Dyer
Elizabeth A. Lundstrom

 

Clara L. Blättler

Clara L. Blättler

Clara L. Blättler is motivated by understanding the processes that shape the Earth's surface and marine environments, and the role these processes have played throughout Earth history. She uses geochemical and isotopic tools to explore connections between the oceans, surface, sediments, and climate. Blättler is currently working with calcium and magnesium isotopes in evaporite and carbonate minerals to learn about ancient seawater chemistry, sedimentary diagenesis, and the geological record of the carbon cycle.

Department/Program(s): Geosciences
Position: Research Staff
Title: Postdoctoral Research Fellow
Office: 210 Guyot Hall
Phone: 609-258-0836
Email: blattler@princeton.edu
Curriculum Vitae

Jack Murphy

Jack Murphy

Jack Murphy came to Princeton after studying physics and philosophy at Bates College, volunteering with the Peace Corps in Southern Africa, and teaching high school for several years.  Murphy's research is motivated by a fascination with the complexity and the long-term stability of Earth's climate system.  Using isotope geochemistry and a range of numerical Earth system models, he studies the processes that regulate climate throughout Earth's History – in particular the silicate weathering feedback, often called “Earth's CO2-thermostat."

Department/Program(s): Geosciences
Position: Graduate Student
Office: 208 Guyot Hall
Phone: 609-937-9817
Email: jackmurphy@princeton.edu

Nicolas W. Slater

Nicolas W. Slater is a Research Specialist I for Higgins Research Laboratory.

Department/Program(s): Geosciences
Position: Research Specialist I
Office: 208 Guyot Hall
Phone: 414-651-1296
Email: ns12@princeton.edu

 

Danielle P. Santiago Ramos

Danielle Santiago Ramos

Danielle P. Santiago Ramos' research is mostly focused on the application of new isotope systems (Ca, Mg, Li, K) to understanding processes that lead to secular variations in the chemistry of the ocean. As an example, she is interested in applying Ca and Mg isotopes to better understand the sparse record of dolomites through time, and its relationship with the evolution of the ocean’s magnesium isotope composition. Additionally, Santiago Ramos has been working on measuring the potassium isotope composition of terrestrial materials with the ultimate goal of improving our knowledge of the biogeochemical cycle of potassium, a major component in the ocean and continental crust.

Department/Program(s): Geosciences
Position: Graduate Student
Office: 210 Guyot Hall
Phone: 609-258-9817
Email: dpramos@princeton.edu

 

Yuzhen Yan

Yuzhen Yan

Yuzhen Yan obtained his B.S. in Environmental Science from Peking University. He is currently working on the ice cores drilled in Allan Hills Blue Ice Areas, East Antarctica in the 2015-16 field season. Allan Hills could potentially preserve ice older than 2 million years, providing an exciting opportunity to study the Antarctica climate and atmospheric composition since the early Pleistocene. Yan's advisers are Professors Michael Bender and John Higgins.

Department/Program(s): Geosciences
Position: Graduate Student
Office: 157 Guyot Hall
Phone: 609-258-4674
Email: yuzheny@princeton.edu