Faculty

.

Guy Dagan

Senior lecturer
Read More
Research interests
The Earth’s radiation budget and future climate change are intricately linked to clouds and aerosols. Efforts to accurately predict future climate, and socially adopt to it, are hampered by our limited understanding of how aerosols, clouds, circulation and climate interact. My main research interest is in trying to better understand the role of clouds and aerosols in the climate system. In order to do so I mostly use numerical models of different scales (from the single cloud scale to the global scale). Today’s state-of-the-art climate models, which are the main tool for predicting climate change, cannot work with the sufficient resolution required to directly solve the relevant physical processes related to clouds. This inability hampers our efforts to account for the clouds’ role in climate change and to predict future climate. On the other hand, high-resolution, limited-area, cloud resolving simulations are unable to directly account for the changes in the dynamics and thermodynamics of the climate system, hence they lack an important component of the clouds response. I believe that cerfully combining these tools (limited-area high resolution simulations and global simulations) together with observations is the preferred way to improve our understanding.    
 

 

Read Less
Ori Adam

Ori Adam

Senior Lecturer
Head of the academic committee of the Hebrew University Climate Science Center (HUCS)
Academic head of the Hebrew University Research Computing Service
Room 307 North
972-2-6586514

Read More
In my group we study the large-scale dynamics of the atmosphere and oceans and the interactions between them, with emphasis on tropical climate dynamics. We aim to improve our understanding of variations in the present and past climates, and the governing dynamic and thermodynamic mechanisms that drive them. We also strive to mediate between theoretical and applied geophysical practices, by developing tools and methods for applications such as bias reduction in climate models, interpretation of paleo records, and quantification of variations of the tropical rain belt.
 

The theoretical tools we use include idealized models of the atmosphere and oceans which are amenable to mathematical analysis, an idealized general circulation model (FMS), as well as the analysis of comprehensive climate models (e.g., CMIP and PMIP models). We also aim to anchor the research in observations. To handle the large variety of observational and modeling datasets, we use a software tool called GOAT (Geophysical Observation Analysis Tool).

Current research projects include:

  • Idealised coupled cloud-ocean-atmosphere models
  • The effect of continent distribution on tropical climate
  • The relation of the atmospheric energy budget and tropical precipitation
  • Origin and nature of the double ITCZ bias
  • Variations of the tropical rain belt in the present and past climates
  • Relating the Hadley cell strength to the atmospheric energy budget
 
Read Less
Hagit Affek

Hagit Affek

Associate Professor
Room 201 North
972-2-6584654

Read More

My research focuses on global climate change and the use of isotope geochemistry to understand climatic and atmospheric processes. I am interested in the parameters and mechanisms that control paleotemperature proxies; in particuler, my group develops and uses the novel proxy carbonate clumped isotopes. We examine biological parameters that affect clumped isotopes and develop its use in new archive materials; we study the effect of non equilibrium processes on clumped isotopes and oxygen isotopes. We apply clumped isotpes to reconstruct paleotemperature and paleo-rainfall in different time periods during the Cenzoic. I am also interested in the use of isotopes to understand the modern carbon cycle and the effect of the biosphere of atmospheric chemistry.

 

What is clumped isotopes geochemistry?

Analysis of an isotopic composition is a measurement of the relative abundance of a heavy, rare, isotope within a group of molecules. The term ‘clumped isotopes’ refers to the natural abundance of molecules containing two heavy isotopes, such as 13C18O16O, and is a measure of the preference of two heavy isotopes to clump together into a chemical bond. This preference is temperature dependent with the isotopes distributed randomly among all molecules at very high temperatures and are clustered together into a more ordered system at low temperatures.

This results in an isotopic parameter, ∆47, that can record the temperature in which these bonds were formed. ‘Clumped isotopes’ measurements are currently applied for 13C-18O bonds in CO2 molecules that are extracted either from carbonate minerals or from the atmosphere. In carbonates ‘clumped isotopes’ are used to determine the formation temperature of the mineral with most applications associated with reconstruction of past climatic conditions. In atmospheric CO2 it is used as a tracer for partitioning and quantifying the different CO2 sources and sinks of the global carbon cycle.

 

Curriculum Vitae

 

Read Less
Einat  Aharonov

Einat Aharonov

Professor
Room 311 South
972-2-65-84670
Read More
Research Interests
 
In my group, we study coupled physical and chemical processes that control deformation and evolution of rocks. Most of our research focuses on how relatively small-scale processes (on the pore, grain, or asperity scale) control large-scale geological phenomena such as soil liquefaction, the dynamics of landslides and earthquakes, the process of rock compaction/dissolution, or the physics of friction. My group also studies larger scale coupled deformation, such as coupled brittle - ductile deformation, the creation of pockmarks on the ocean floor, salt tectonics and the physics of subduction initiation. I work on the boundary between physics and geology, using mainly theoretical and numerical tools. However, our work is always constrained by observations: to understand the physics of a system of interest, I collaborate also with field geologists and experimentalists who provide an empirical foundation to the theoretical work.
 
In addition, recently I became interested in Energy issues, especially in oil & gas formation and extraction, and their environmental and climatic impact. I formed and headed the Petroleum Geology MSc direction at the Hebrew University.  
 
Ongoing projects:
  • The physics of friction – can we predict friction, and dependence on velocity, temperature and pressure, from basic thermodynamic parameters?
  • Understanding how salt tectonics causes faulting of overlying sediments.
  • The physics of soil liquefaction during earthquakes.
  • Earthquake triggering by fluids. 
  • Reactive flow in rocks and formation of hyopgenic karsts.
 
Past PhD Students and postdocs:
  • Dr Zvi Kul Karcz. VP for Exploration and Chief Geologist at Delek Drilling Company.
  • Prof Liran Goren, Associate Prof at the Department of Earth and Environmental Sciences, Ben-Gurion University, Israel.  
  • Dr Stanislav Parez, Researcher at the Inst of Chemical Process Fundamentals, The Czech Academy of Sciences.
  • Dr Regina Katsman, Scientist at the Dept of Marine Geosciences, Univ of Haifa.
  • Dr Shalev Siman-Tov, Researcher at the Geological Hazards Division, Geological survey of Israel
  • Dr. Nataliia Makedonska, Scientist at Computational Earth Science Group, Los Alamos National labs, USA.
  • Dr Anner Paldor, postdoc at the Univ. of Delaware, Dept. of Earth Sciences.
  • Dr Leehee Laronne Ben-Itzhak
 
 
Past MSc students: Inbar Vaknin, Einav Reuven, Hanna Rubin, Itzhak Hamdani, Maor Kaduri. Boriana Kalderon‐Asael, Yonatan Elfassi.
 
 
Present postdocs: Dr Maor Kaduri.
 
 
Present PhD students: Shahar Ben Zeev, Roi Roded, Pritom Sarma, Jimmy Moneron (main advisor Prof Z Gvirtzman).
 
 
Read Less
Alon  Amrani

Alon Amrani

Associate Professor
Head of the Environmental Science Department
Room 204 North
972-2-65-85477

Read More

Interests: 

Organic geochemistry and biogeochemistry, stable isotopes, sulfur cycle, organic-inorganic interactions

 

 

Read Less
Alon Angert

Alon Angert

Professor
Room 217 South
972-2-65-84758

Read More

 

 

Climate Change affects the terrestrial biosphere, while changes in the biosphere feedback and affect the climate system. Understanding these complex interactions is important at these times of Global Change.

Related research in our lab track the respiration in soils, and the internal CO2 movement and recycling within forest trees. In addition, we explore the engagement of the Alternative Oxidase in natural ecosystems. These research directions are based on high accuracy measurements of O2 concentrations and stable isotopes.

Other research projects focus on developing the use of oxygen stable isotopes of phosphate for tracking phosphorus in dust and its biogeochemical cycling in soil. This research is based on field work, remote-sensing and lab work. These approaches could help evaluate the effects of changing climate on the terrestrial phosphorus cycle, which is an important limiting factor for plant growth.

Finally, lately we have developed in collaboration with Prof. Amrani, from my institute, an approach to measure the sulfur isotopes of carbonyl sulfide (COS) and used this to determine its isotopic composition in the atmosphere in plant uptake, and in seawater. Our continued research in this field will help to better constrain global scale photosynthesis

 

Curriculum Vitae

angert lab

 

 

 

 

 

 

 

 

 

 

 

 

 


Terrestrial Biogeochemestry- Angert's lab Group

 
 

Tal Weiner - Lab Manager

Research Interests: The study of soil phosphate and its sources using stable isotopes analysis

 
chen davidson  

Chen Davidson - Phd student

Research interests: Studying sulfur isotopes of Carbonyl Sulfide in the atmosphere and in seawater, to better constrain the terrestrial global photosynthesis

 

 
 
 
 
 
 
 
 
 
 
Aline Naor  

 Alie Naor - Msc student:

Research interest: The effect of cellular PO4 uptake on the isotopic signature of extracellular phosphate in macrophytes and aquatic fungi. 

 

 
 
 
 
 
 

 

 

 

.  

Yasmin Avidani - Msc student:

Research interest: Studying the oceanic source of COS and CS2 by sulfur stable isotopes, in aim to improve quantifications of global photosynthesis.

 

Former Members

Laura

 

Laura Bigio - Former Phd student

Research Interests: Atmospheric phosphate sources (dust, ash and pollen) and their contribution to the global phosphorus cycle.

 

boaz

 

Boaz Hilman - Former Phd student

Currently: Post Doctoral researcher at Max Planck Institute for biogeochemestry 

http://www.bgc-jena.mpg.de/bgp/index.php/Site/Hom

 

H Lis

 

Hagar Lis - Former Post- Doctoral Researcher 

Currently: Associate researcher at the Plant science department at the Hebrew University.

 

avner

 

Avner Gross - Former Phd student
Currently: Assistant Prof. at the Ben Gurion University of the Negev 

http://in.bgu.ac.il/humsos/geog/pages/staff/avnergross.aspx

 

 

Sasha Pekarsky - Former Msc student

Research Interest: Crane Migration study with oxygen stable isotopesCurrently: http://huji.move-ecol.com/users/sasha-pekarsky

 

 

Esther Peled            

Esther Peled - Former MSc Student 

Currently: Head of Sustainability and Environment - Sustainability and  CSR Group at BDO Israel

 il.linkedin.com/in/esther-peled

 
שרית  

 

Sarit Shaltiel - Former MSc Student 

 

 

dust sampling
 

 

 

Read Less
Dov Avigad

Dov Avigad

Professor
Room 204 North
972-2-65-86468

Read More

Together with my students, postdoctoral scholars, and affiliated researchers, I combine field and laboratory studies to understand the origin of Earth's continental crust, its composition and architecture. Within this broad research avenue I concentrate on aspects of continental tectonics with emphasis on Precambrian crustal evolution, old and young orogenic belts, continental extensional tectonics, and the link between orogeny, erosion and sedimentation. We seek to unravel plate tectonics processes around the Eastern Mediterranean with special emphasis on the Cadomian and Avalonian continental collage of SE Europe and Asia Minor, Precambrian crustal evolution of the Arabian-Nubian Shield in Eilat and Ethiopia, the provenance of the great Paleozoic sand sea of northern Africa and Arabia, and its linkage to Pan-African orogens and to coeval silisiclastic sediments in Europe.

Our research is funded by the Israel Science Foundation, the Israel Ministry of Infrastructure, the German-Israel Binational Science Foundation and the USA-Israel Binational Science Foundation. We currently collaborate with scientists from Israel, USA, Australia, Germany, Turkey, France and Ethiopia

 

Curriculum Vitae

 

Read Less
Simon

Simon Emmanuel

Professor
Room 306 South
972-2-65-86875

Read More

Our group studies nano-scale geological processes central to hydrology and the oil and gas industry. We use a diverse array of methods, combining cutting edge lab technology, state-of-the-art modeling, and field work. Current research projects include:

  • Measuring mineral reaction rates during geological carbon sequestration
  • Imaging crystal growth in nano-pores
  • Analysing mechanical properties of rocks at the nano-scale

I am currently looking for creative students with backgrounds in Earth Sciences, Chemistry, and Physics to join our team. Students in the group are part of a dynamic research program that is developing exciting new projects at the interface between hydrology, geology, and geochemistry. For further information concerning MSc, PhD and postdoctoral opportunities, contact Dr Simon Emmanuel (swemmanuel@gmail.com).

Read Less
yigal

Yigal Erel

Kozenitsky-Rosenbach Professor of Geology
Room 007 North
972-2-65-86515

 

Read More

My research involves the application of trace-element ratios and Sr, Nd, Pb, Mo and Fe isotopic compositions to follow the fate of metals in the environment, in archaeological artifacts and in humans. The clean lab and our sensitive analytical instruments enable me and my students to study small-samples and/or materials with low elemental concentrations (e.g., dust samples, teeth and brain). Currently, my group is involved in research projects centering around:

1.     Records of aeolian, fluvial and lacustrine sediments as tracers of paleo-environment conditions and sediment sources.

2.     Tracing metal artifacts in antiquity.

3.     The dark side of ancient metallurgy: Measuring toxic metals and metallic isotopes (and aDNA) in human populations and in artifacts to trace the impact of early industries through time.

4. The association between elemental anomalies in the human brain and mental diseases.

We carry out these projects in collaboration with researchers from the Hebrew University (Earth Science, Archaeology, Medicine), the Geological Survey of Israel, Israel Oceanographic and Limnological Research, The Israel Antiquities Authority, Tel Aviv University, Haifa University, GFZ - Potsdam, Germany, Columbia University, University of California San Diego, University of Michigan, and the Institute of Geology and Geophysics, Chinese Academy of Sciences. 


 

Read Less
Chaim Garfinkel

Chaim I. Garfinkel

Associate Professor
Head of the Graduate program in Atmospheric Sciences
Room 316 North
972-2-658-4944

Read More

Research Interests: 

Large-scale atmospheric and climate dynamics/variability 


Atmospheric dynamicists try to understand why the atmosphere moves in the way it does. Because of the inherently chaotic nature of the atmosphere, and because the atmosphere is strongly linked to the oceans, land-surface, biosphere, the types of interactions that occur are very complex. However, a wide range of tools, ranging from observational data to simplified models, can help atmospheric dynamicists understand (and even predict) atmospheric motions.
 
 

More specifically, my research aims at extending the duration of reliable weather forecasts, and to then explore how the dynamical processes that are important on these short timescales may manifest on longer, climate-change timescales. The traditional approach to weather forecasting on one- to two-week timescales utilizes weather forecasting models, but on timescales longer than two weeks, the value of deterministic (or ensemble-based probabilistic) forecasts weakens. This is due to the presence of chaotic variability in the atmosphere. Yet certain modes of variability in the climate system have timescales longer than this two-week threshold, and the key to longer-scale prediction is to take advantage of these modes. By understanding the impacts of these modes of variability on surface weather, the potential for improved forecasts on a monthly timescale can be demonstrated and eventually realized. As many of these processes may be modified under climate change (or alternately, climate change may project onto these climate modes), a better understanding of these modes can also help improve the quality of climate change projections.

Two such classes of modes of variability are stratospheric variability (both in the tropical and polar stratosphere) and tropical tropospheric variability (e.g. the Madden-Julian Oscillation and El Nino), and most of my ongoing research focuses on these phenomena. For example, both polar stratospheric sudden warmings and the Madden-Julian Oscillation have been shown to influence European and Mediterannean weather, but it is unclear (1) what mechanism(s) underlie these connections, (2) how far in advance the  impacts can be predicted, and (3) what governs the magnitude of the surface impact.  As these processes must be represented by climate and weather models in order to actualize the potential improvement in predictability, and because the observational record of key meteorological quantities is relatively short, I also run models (both idealized and comprehensive) in order to test model fidelity and to isolate key processes. The ultimate goal is to improve the predictions and projections of surface weather and climate.

Opportunities: Exciting, funded opportunities for further research exist in these areas for master's students, PhD students, and postdocs. For more information, please contact me.

Curriculum Vitae

 

 

Mailing address:
 The Fredy & Nadine Herrmann Institute of Earth Sciences
 The Hebrew University Edmond J. Safra Campus,
 Givat Ram Jerusalem, 91904 Israel

 

Read Less
Yoni Goldsmith

Yonatan Goldsmith

Senior Lecturer
Room 14 South

Read More

Research Interests 

Understanding how global warming will effect water availability is one of the crucial questions of our time.

My research is aimed at quantifying past changes in rainfall and evaporation in different places around the world (China, Mongolia, western US, Middle East) in order to understand the natural variability of rainfall and evaporation and the processes that govern this variability.

I combine geomorphology with isotope geochemistry (compound specific stable isotopes (dD, d13C), traditional stable isotopes (dD, 18O, d13C), clumped isotopes and U/Th dating) to investigate how the status of lakes has changed through time. I use hydrological models and outputs of climate models to quantify and evaluate the empirical data I collect.

I’m also interested in how human societies respond to climate change throughout history and in the present.

Ongoing projects:

  • Quantifying the migration of the East Asian Monsoon during the Late Quaternary in China and Mongolia
  • Reconstructing paleo-intensity of the Indian Monsoon using lake-area fluctuations from Lake Chenghai, Southern China
  • Developing and applying compound specific stable isotope biogeochemistry to problems in terrestrial hydroclimate, East Asia, West Asia, Western USA
  • Chemical and isotopic processes of shoreline tufa formation in Mono Lake, USA.

Curriculum Vitae

Read Less
Carynelisa Haspel

Carynelisa Haspel

Associate Professor
Head of the Undergraduate Specialization in Climate, Atmospheric Sciences, and Oceanography (CAO)
Room 302 North
+972-2-658-4974; +972-54-2122328

Read More

Research

Scattering of Electromagnetic Radiation by Irregular Particles in the Atmosphere and Ocean

I work with models that describe the interaction of solar radiation with particles in Earth's atmosphere and oceans. I am particularly interested in how best (both accurately and efficiently) to model the effects of irregular particles, such as non-spherical particles, porous particles, and particles comprised of disorded/amorphous materials. Similarly, I am interested in how best to model mixtures of different components in the same particle. What are the differing effects of insoluble vs. soluble, solid vs. liquid, and absorbing vs. nonabsorbing components?

 

Underwater Polarization

While human beings only detect the intensity and wavelength of light, some species, both terrestrial and marine, are able to sense light's third attribute, polarization. Such species use polarization (the direction of the electric field) for different tasks such as orientation, navigation, prey detection, and communication. Under water, where the intensity signal is distorted by refraction and weakened by absorption, the ability to utilize polarization can be even more important than on land. For many years, theoretical models of polarized light under water were based on the theory of single scattering of the direct solar beam by small particles (Rayleigh scattering). Models accounting for scattering by larger particles (Mie scattering) have been approximate, and the most sophisticated models to date do not separate the effects of Mie scattering from effects of non-sphericity and multiple scattering. Furthermore, recent measurements under water reveal deviations from the polarization patterns predicted by models, in clear as well as semi-turbid waters. We are using a step-by-step approach to analyze the separate effects of particle size, particle size distribution, particle composition, particle shape, and varying orders of scattering on the underwater polarization pattern, with the goal of identifying the processes at play in different water types.

 

Light Pollution and the Light Environment Within Caves

My group has collaborated with scientists from Bar Ilan University and Beit Berl College in conducting the first in situ measurements ever of artificial nighttime light under water in a coral reef ecosystem. We found that the artificial light can penetrate to a depth of 30 m under the water, which could influence such biological processes as the tuning of circadian clocks, the synchronization of coral spawning, recruitment and competition, vertical migration of demersal plankton, feeding patterns, and prey/predator visual interactions. Similarly, we have collaborated in conducting the first in situ measurements ever of the state of light polarization within a mid-littoral cave. We found a relatively high degree of linear polarization of the light and a nearly constant orientation of the electric field of the light in winter months, which would improve the ability of the photosynthetic organisms there (cyanobacteria, microalgae, and macroalgae) to harvest light by orienting their light-harvesting receptors to the direction of the electric field.

 

Atmospheric Electricity

At Hebrew University, we have an ongoing collaboration with Tel Aviv University, The Open University, and the IDC Herzliya to study transient luminous events (TLEs), such as sprites, blue starters, jets, and elves, which occur above thunderstorm clouds. We have conducted our own observations of sprites and have constructed simple theoretical models to help explain some observed phenomena, such as the circular configuration of simultaneous sprites and the shift in the location of sprites from their parent lightning event.

 

Radiative Forcing of Climate

We look at how the presence of various types of particles affects the Earth's radiative-convective balance. Which particles cause a warming and which cause a cooling, and how does this change with their horizontal distribution? What is the most accurate way of representing subgrid scale features, such as inhomogeneous aerosol and cloud layers, in global models?

 

Curriculum Vitae

Read Less
photo credit:  Moti Milrod

Assaf Hochman

Senior Lecturer
309 North

Read More
Lab name: Predictability of Extreme Weather (PredEx).

Interests:  Dynamics and predictability of extreme weather; Climate change; Paleoclimate modelling; Large-Scale circulation; Exoplanet climate dynamics; Public health adaptation to climate change

Research Interests 

The predictability of weather and climate is the estimation of uncertainty in model predictions. Atmospheric predictability is strongly dependent on the accuracy of initial conditions, on the representation of sub grid-scale processes and on climate change scenarios. The main purpose of my research is in reducing extreme climate and weather prediction uncertainties across spatial and temporal scales, especially over vulnerable populated regions. My work addresses the issue of weather and climate predictability from different perspectives including physical observations, computer modelling and mathematical/statistical theory.

 

Ongoing and future projects

  • Sub-seasonal Predictability of Hydrological Extremes in the Eastern Mediterranean (SPredHex).
  • Towards Implementing Dynamical Systems Tools for Extreme Weather Prediction over the Middle East and Israel (EMedPredEx).
  • Understanding Dynamics and Predictability of Extreme Mediterranean Cyclones (PredCEx).
  • Understanding Extreme Climate Characteristics in the Levant from a Regional Modelling Perspective (PredExClim).
  • Developing a dynamical systems framework for the broad range of terrestrial exoplanet climates (ExoClimDyn).
  • The Influence of Extreme Weather on Public Health in the Eastern Mediterranean (ExHealth).

Opportunities: Exciting, funded opportunities in these areas for M.Sc and PhD students as well as postdoctoral research associates.

For more information, please contact me: assaf.hochman@mail.huji.ac.il

 

Read Less
Ronit  Kessel

Ronit Kessel

Associate Professor
Head of the Geology Program
Room 210 South
+972-2-65-85584

Read More

 

The combination of experimental petrology and thermodynamic modeling provides powerful insights into the igneous and metamorphic processes by which Earth and other planets evolved.  My research involves the development of experimental techniques together with modeling of the experimental data to constrain the nature of both terrestrial and extraterrestrial environments through the study of synthetic analogs. 

The topics I am currently involved with:

Melt and fluid compositions in equilibrium with mantle material. Aqueous fluids play an important role in melting and metasomatism of the Earth’s mantle; I study the role of volatiles (H2O, CO2, etc.) in dehydration/hydration and melting processes in the mantle.

The evolution of meteorite groups. Samples delivered to the Earth as meteorites provide us with a unique opportunity to study the timing and the processes by which our solar system formed and evolved.  I combine both experimental and analytical methods to understand the formation conditions of different groups of meteorites.

 

Curriculum Vitae

 

Read Less
.

Nadav Lensky

Associate Professor (Adjunct)
+972-50-6235197  
Read More
Interests:  Geology, Limnogeology of the Dead Sea, from evaporation to evaporites, air-water interactions, fluvial and coastal geomorphology
 
My research focuses on basic questions regarding the controlling processes of large scale Earth environments, and the relations between climatic/environmental conditions and the formation of geological records in un-balanced systems. I try to stick to the useful approach - “the present as a key to the past”. The Dead Sea, a deep hypersaline lake subjected to negative water balance that precipitates salt layers, is a unique aquatic system on Earth today, which provides a rare opportunity to explore the formation of “salt giants”, i.e. ~kilometer thick salt layers in wide sedimentary basins that were common aquatic environments in the past. In addition, the Dead Sea vicinity is a multi-setting natural laboratory for rare exploration of geomorphic responses to base level fall. With my students, we tend to start our explorations with direct observations, using buoys in the Dead Sea measuring air-water exchange (eddy-covariance towers), the properties within the water column, the formation of salt deposits and their variation in time and space, and we perform seasonal surveys of the lake floor using Remotely Operated Vehicle (ROV). The observations are then arranged in theoretical schemes including conservation and transport equations to allow generalization of our findings.
​Ongoing and future projects:
  • “From evaporation to evaporites” – the relation of environmental/climatic forcing, through the thermos-haline stratification of the water column and transport processes between the strata, to the formation of salt layers, including temporal variations (diurnal and seasonal cycles, and synoptic events) and spatial variations along climatic gradients and depth variations within the lake.
  • Stratigraphy and sedimentology of salt and detritic layers during lake regression – high resolution observations relating hydroclimatic conditions to rock textures and composition.
  • Surface processes in response to lake level lowering – stream incision and the transport of sediments by fluvial and coastal conveyers.  
  • We now expand our activity to the next water bodies along the Dead Sea rift (Hula, Kinneret, Dead Sea and Gulf of Eilat), where we explore the gas, heat and momentum exchange across the water surfaces, and their impact on the water body and the deposits. These water bodies are arranged within a tectonic rift, and along an extreme climatic gradient, with various aquatic biology.
 
Get in touch: nadavl@gsi.gov.il
Read Less
.

Itzhak Lior

Senior Lecturer
14 south
+972-545-991747  

 

Read More

Interests: Earthquake Seismology, Distributed Acoustic Sensing, Earthquake Early Warning, Source Parameter Inversion, Ground Motion Prediction

Research Interests

The relation between the processes at the earthquake source and the seismic waves recorded at the Earth’s surface is key for many seismological purposes. In my research, I am combining theory and observations to gain new insight into the effects of the different source properties (such as magnitude, stress drop, directivity) on the resulting ground motions. I then use this understanding for various practical and theoretical aspects including earthquake early warning (EEW), ground motion prediction equations (GMPE), source parameter inversion, studying the differences between small and large earthquakes, predicting the damage potential, and more.

Recently, I am using distributed acoustic sensing (DAS) applied to optical fibers. This new technology transforms standard telecommunication cables into tens-of-kilometers long seismic arrays, allowing for ground motion measurements every few meters in a high-resolution low cost approach. These new observations allow us to study earthquakes, ocean waves, ambient seismic noise, image subsurface geological structures, and more. DAS is a game changer in seismology since it allows for seismic recordings in hard to access regions (underwater, in boreholes), and provides abundant observations for new and exciting scientific discoveries.

 

Curriculum Vitae

Read Less
.

Ari Matmon

Professor
Head of The Earth Science Institute
972-2-65-86703

 

 

Read More

Understanding surface processes and erosion across the Atacama Desert, Chile

 The Atacama Desert is thought to be the most arid region in the world. Indeed some of the slowest erosion rates have been measured in this area. In this study we collected sediment from active channels and alluvial fans from the Pacific coast to the Andean foothills in order to quantify landscape processes. Estimated rates of erosion from bedrock and sediment, even in the absolute desert are comparable to rates estimated from other deserts.  In contrast, boulders are unique landscape elements that essentially do not erode; the fact that these boulders do not erode may explain their accumulation in large “boulder fields”.  Boulder fields were also investigated to understand the role of seismicity in the evolution of landscapes in the Atacama Desert. This project is done in collaboration with Christa Placzek, James Cook University, Queensland, Australia, Jay Quade, University of Arizona, Tucson, and Darryl Granger, Purdue University.

Atacama desert

 

Understanding surface processes in carbonate terrains 

In carbonate terrains denudation rate and style (mechanical or chemical) are very sensitive to climatic forcing. Using 36Cl measurements in carbonate bedrock and sediment samples, long-term denudation rates were calculated across a sharp climatic gradient from Mediterranean to hyper-arid conditions. Denudation rates of flat-lying bedrock outcrops range between ∼20 mmka1 in the Mediterranean zone and 1–3 mmka1 in the hyper-arid zone. These rates are strongly correlated with precipitation, and thus reflect the importance of carbonate mineral dissolution in the overall denudation process. A transition between chemically-dominated denudation to mechanically-dominated denudation occurs between 100 and 200 mm of mean annual precipitation. It is demonstrated that carbonate terrains have the capacity to shift between mechanically and chemically dominated denudation in response to changes in precipitation. Dr. Uri Ryb has recently completed his PhD investigating these carbonate terrains.

carbonate terrains

Landscape evolution and coseismic aspects of sandstone boulder piles

Rockfall ages in tectonically active regions provide information regarding frequency and magnitude of earthquakes. Rockfalls along the hyper-arid western margin of the Dead Sea fault (DSF) were dated using terrestrial cosmogenic nuclides (TCN). Results indicate rockfall ages between 3.6 ± 0.8 and 4.7 ± 0.7 ka.  These ages agree with dated earthquakes determined in paleoseismic studies along the entire length of the DSF and support the observation of intensive earthquake activity around 4–5 ka. This project was the focus of MSc project of Mr. Yair Rinat. Further advances in investigating boulder ages using cosmogenic isotopes and relating them to seismic activity along the DSF was achieved by post doc Dr. Alan Hidy.

sandstone boulder piles

 

Reconstructing the history of sediment deposition in caves: A case study from Wonderwerk Cave, South Africa

 We applied cosmogenic isotope burial dating, magnetostratigraphy, and grain-size distribution analysis to elucidate the history of the sedimentary sequence of the Wonderwerk Cave, located on the southern edge of the Kalahari Desert, South Africa. Our results suggest most likely burial ages for sediments from both the front and back of the cave that range between 1.85 ± 0.23 and 0.78 ± 0.18 Ma. The correlation of paleomagnetic results with the cosmogenic burial ages is complicated and suggests the affect of chemical and physical processes on the acquisition of the palemagnetic signal. Aspects of landscape evolution, both immediately outside the cave and on a regional scale are investigated within the scope of this project. The cosmogenic burial ages also constrain the period in which the cave was inhabited by hominids and points to the first known controlled use of fire. This project is done in collaboration with Prof. Michael Chazan from the University of Toronto, Canada, and Dr. Liora Hurwitz, from the Hebrew University in Jerusalem.

Wonderwerk Cave, South Africa

Chronostratigraphy and Geochemistry of Kalahari group sediments in the southern Kalahari basin

The Kalahari is a mostly-flat and gently undulating landscape that ranges in elevation between 850 to 1,500 m a.s.l. Most of the 2.5 million km2 of the Kalahari are semi-arid and are covered by an extensive blanket of unconsolidated sand comprising one of the largest continuous sand bodies on Earth. Sediments that have been deposited in the Kalahari since the Cretaceous are defined as the Kalahari Group; their thickness varies and reaches up to ~450 m. The flat landscape of the Kalahari results in limited exposure of the underlying rock column. The most significant exposure of the Kalahari Group in the southern Kalahari is located at the Mamatwan manganese mine. This section is comprised of ~55 m of Kalahari Group sediments that lie uncomfortably over the 2.2 Ga Protorozoic deposits. This research focuses on the chronostrtigraphy and the geochemical composition of the Kalahari Group sediments in the Mamatwan Mine section. It is done by PhD student Shlomy Vainer.

Kalahari basin

 

Applying cosmogenic in-situ 21Ne as a tool for investigating surface processes in 108 year sedimentary cycles

Quantifying surficial processes is of major importance to studies of continental evolution and landscape change. In this study we measure the concentration of the stable cosmogenic nuclide 21Ne and test whether it can be used to quantify erosion rates throughout the Phanerozoic (>107 yr). This new tool will be of immense value in the research of tectonic and geodynamics of continental terrains. Cosmogenic 21Ne accumulates through multiple episodes of exposure. The passive margin of Gondwana offers a setting to test cosmogenic 21Ne as a tool for paleo-geomorphological research as well as determine the rates of surface processes since the establishment of the Pan African shield, ~540 Ma. Preliminary results are consistent with the hypothesis of increasing 21Ne concentrations with decreasing age and suggest that in the temporal scale of a sedimentary cycle, sediments spend most of their time buried and are in transport for only a very short time. This project is done by PhD student Michal Ben-Israel.

sedimentary cycles

 Aggradation and Incision in the NE Negev, Israel, during the Pleistocene and Holocene

In this study the behavior of drainage systems in an arid climate that is not affected by fluctuations in base level is investigated. Pleistocene and Holocene alluvial terraces were mapped and dated to ~1.1 Ma, ~300 Ka, ~100 Ka, ~20 Ka, ~12 Ka and ~3 Ka. All alluvial terrace surfaces include gypsic-salic soils typical to hyperarid climate.  No pedogenic indicators of past wetter environments such as buried calcic soil horizons or buried organic material were observed. The pedogenic evidence, combined with the abandonment ages of the terraces suggest that climatic changes did not control alternation between sediment aggradation and degradation. Storage of sediments on the slopes and evidence form boulders that accumulated high 10Be concentrations indicate that availability of sediment is not the limiting factor for sediment aggradation. The limiting factor is the ability of the drainage system to transport the sediment. This study was recently completed by master student Shlomo Alfasi.

Negev, Israel

 

Aggradation-incision relationship in the Late Pleistocene in Negev Highlands, Southern Israel

A significant indicator of environmental change in arid regions at the end of the Pleistocene is the transition from fine-grained sediment deposition to intensive incision. To investigate this transition, three basins in the arid region of the Negev Highlands, southern Israel, were studied. Geomorphological survey, particle size distribution analysis, and OSL dating, show that: 1) during the last glacial, fluvial loess was widely deposited until at least 29 ka, 2) as a result of significant decrease in dust supply, 29-24 ka, loess was washed from the slopes into the channels, revealing the underlying colluvium, 3) at 24 ka the erosion process initiated with re-deposition of slope colluvium within the valleys and intense incision, which is still ongoing, initiated at 13 ka. It is shown that the reduction in aeolian loess supply was the trigger for erosion and incision. This project was completed recently by master student Gala Faershtein and was done in collaboration with Dr. Yoav Avni and Dr. Naomi Porat from the Israel Geological survey.

Late Pleistocene in Negev Highlands, Southern Israel

Extending luminescence dating into the Early Pleistocene – method development and application to the Coastal Plain, Israel

Dating of continental clastic sediments of early Pleistocene age is a challenge. Optically stimulated luminescence (OSL) is a strong tool for dating Pleistocene to Holocene sediments. However, standard OSL technique is usually limited to 200-250 ka. The Israeli Coastal Plain sequence spans the Pliocene to recent. Its younger part has been intensively dated. The chronology of the older units of the Coastal Plain sequence is derived from limited measurements of palaeomagnetic reversals and a few cosmogenic radionuclide ages. New, extended-range luminescence techniques (TT-OSL, VSL, ITL) show a great potential for dating sediments of middle to early Pleistocene. There are still unsolved problems concerning the optimal use of these techniques. The aim of this study is to establish the extended-range luminescence dating techniques to allow reliable dating of buried sediments throughout Quaternary and late Pliocene. This research is done by PhD student Gala Faershtein.

Coastal Plain, Israel

 

Spatial off- axis Tectonic Deformation along the southern Arava segment of the Dead Sea transform as expressed by geomorphic indications.

Tectonic and seismic activity along the southern Dead Sea fault (DSF) has been intensively studied. However, our understanding of young off-axis deformation in this region remains less clear. This study focuses on understanding the spatial distribution of late Quaternary tectonic deformation through interpretation of changes in drainage systems. Geomorphic evidence were found for tilting of fan sequences towards a common axis suggesting on-going crustal compression. OSL dating indicate that deformation leading to the observed geomorphic perturbations spans from late Pleistocene to middle Holocene. This research shows that the spatial extent of tectonic deformation along the southern DSF is wider than previously considered and is the result of changes in the geometry of relative movement between the Arabian and the Sinai plates. This project has been recently completed by master student Yedidya Gelman.

 

 Coastal Plain, Israel

Dating Quaternary landslides along the margins of the Jordan Valley – implications for rift development and interaction between rift water bodies and margin stability

The Jordan Valley is part of the Dead Sea fault (DSF) that has been experiencing tectonic activity since the early Miocene. In this study we will date several landslides composed mainly of basaltic boulders of the Pliocene Cover Basalt formation. Two hypotheses are tested: 1) the landslides are very old (>106 years). In this case the time they were active will constrain the minimum age for the stabilization of the present Jordan Valley base level since the toe of these landslides reach the base of the present Jordan Valley. 2) The landslides are young (~104 years). In the second case, their activity expresses the interaction between Lake Lisan during its highest stand and the margins of the rift.

 

 Jordan Valley

 

 Curriculum Vitae

Read Less
Efrat Morin

Efrat Morin

Professor
Room 308 South
972-2-6584469

Read More

Research Interests:

I am interested in understanding, modeling and predicting dominant processes and interactions of hydrological and meteorological systems at different space-time scales. I am in particular interested in space-time patterns of precipitation fields and how these are related to meteorological controls on one hand and to hydrological impacts on the other. Precipitation data from remote sensing systems (radar and satellite) are often used in my research, where their uncertainty is also considered. With my group we investigate extreme precipitation and floods at a range of scales. We develop and utilize process-based and data-driven models in deterministic and stochastic frameworks. We examine climate variability and climate change in present, past and future conditions and their effects on different environmental systems that are of interest in hydrological, geomorphologic, agricultural and ecological fields of research.

 

Curriculum Vitae

 

Read Less
Dorita_R.E.jpg

Dorita Rostkier-Edelstein

Associate Professor (Adjunct)
Room 304 South
Read More
M3 Lab, Mesoscale Meteorology and Modeling
 
Research Interests 
 
My research focuses on mesoscale meteorology and modeling and pursues to improve numerical weather and climate prediction at high spatial resolution, with special attention to planetary boundary layer (PBL) phenomena. I have put special emphasis on developing data assimilation (DA) approaches that can optimally improve model initial conditions in the PBL by assimilation of observations into the model. Moreover, much of my efforts have been devoted to developing and improving dynamical downscaling methods to efficiently achieve computationally expensive high resolution climatographies (model calculated climatology). In addition, I have developed analogues and weather-regimes based downscaling methods and applied them in seasonal forecasts and future climate predictions of precipitation. The use of observations and models provide me the tools to better understand the physical and dynamical processes responsible for the mesoscale phenomena of interest such as sea-land breeze, foehn and hydraulic jumps, among others. I have dedicated efforts to study meteorological phenomena beyond the PBL including transport of mineral dust. 
 
Ongoing and future projects:
  • Data assimilation of opportunistic observations to improve convection scale precipitation forecasts using WRF model and DART ensemble Kalman filter DA.
  • Mesosocale modeling over urban areas for air pollution applications using WRF model with mesoscale urban parameterizations
  • Analysis of Mediterranean cyclones in present and future global and regional climate models and their connection to precipitation using analogues downscaling methods.
  • Improvement of atmospheric dust-aerosol model by incorporation of a turbulent thermal diffusion parameterization and improved dust-soil emission parameters using WRF-Chem model, laboratory and field measurements.
Curriculum Vitae
 
 
 
Read Less
Uri_riv

Uri Ryb

Senior Lecturer
211 south
+972-2-6584668

Read More

Research Interests 

I'm interested in the interactions among Earth internal processes (tectonic and magmatic), surface processes (erosion and weathering), and their role in the rock cycle, global climate, and the emergence and evolution of life. Over geological time, variations in the style and rate of tectonic activity, climate and ecology alter the compositions of rocks, ocean and atmosphere, and may register as variations in the texture and composition of sedimentary rocks and minerals. In recent years, my research has been focused on the development of new approaches to translate measured geochemical signals in such materials (e.g., clumped-isotope signals measured in carbonate minerals) to quantitative constraints on thermal, compositional and deformational histories of surface, sedimentary basins and metamorphic environments. I have been applying these approaches to study open and closed system reactions during the exhumation of the metamorphic core complex in Naxos (Greece), reconstruct the oxygen isotope composition of the Phanerozoic Ocean, constrain the uplift and exhumation history of the Colorado Plateau, and study the relationship between uplift and exhumation of the Himalaya and the Indian Monsoon intensity, and its potential effect on global climate.

Ongoing and future projects:

  • The Precambrian growth and stabilization of the continental lithosphere and its hypothetical role in the Oxygenation of Earth's atmosphere, global climate, and evolution of life.
  • Reconstructing the oxygen isotope composition of the Precambrian Ocean as a proxy for the proportions of weathering and hydrothermal alteration reactions in deep-time. 
  • Developing new carbonate clumped-isotope based analytical and modeling tools aimed to refine thermal compositional and deformational histories of sedimentary basins and metamorphic environments.
  • Test alternative hypotheses for the ‘Dolomite-Problem’ and the study the relationship between dolomitization and the Ocean Mg/Ca ratio in the geological past.
  • Test various hypotheses linking tectonic uplift and exhumation of the Himalayas to the Indian Monsoon intensity and Cenozoic global cooling.

Curriculum Vitae

Get in touch: uri.ryb@mail.huji.ac.il

Read Less
Yeala Shaked

Yeala Shaked

Associate Professor
Room 16 South
972-8-6360139

Read More

 

Research Interests 

As a marine biogeochemist, my interest revolves around the interactions between organisms and their environment, with emphasis on trace metal bioavailability to phytoplankton and redox transformations. I am intrigued by the fact that microorganisms, striving to acquire nutrients and protect themselves from external stressors, actively modify their chemical milieu and in turn influence the biogeochemical cycles of trace and major elements in the ocean. I study fundamental processes and mechanisms by combining field and laboratory measurements and experiments.

 

Ongoing and future projects:

  • Dust as a source of iron to Trichodesmium, a globally significant phytoplankton
  • Bioavailability of iron to phytoplankton

 

Get in touch: yeala.shaked@mail.huji.ac.il

 

 

Curriculum Vitae

Read Less