Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Environmental Sciences (148)
- Geology (103)
- Oceanography and Atmospheric Sciences and Meteorology (56)
- Hydrology (54)
- Engineering (39)
-
- Life Sciences (37)
- Geomorphology (36)
- Civil and Environmental Engineering (32)
- Environmental Monitoring (31)
- Geochemistry (31)
- Sedimentology (28)
- Sustainability (28)
- Environmental Indicators and Impact Assessment (27)
- Social and Behavioral Sciences (26)
- Water Resource Management (26)
- Soil Science (23)
- Tectonics and Structure (23)
- Climate (22)
- Biogeochemistry (21)
- Paleontology (19)
- Ecology and Evolutionary Biology (16)
- Natural Resources Management and Policy (16)
- Other Earth Sciences (16)
- Stratigraphy (16)
- Astrophysics and Astronomy (15)
- Environmental Education (15)
- Geophysics and Seismology (14)
- Atmospheric Sciences (13)
- Keyword
-
- Remote sensing (15)
- Bangladesh (13)
- GIS (13)
- Climate change (11)
- STEM Education (9)
-
- Geosciences (8)
- Wetlands (8)
- COVID-19 Pandemic (7)
- Hispaniola (7)
- Hydrology (7)
- Provenance (7)
- Experiential learning (5)
- Geology (5)
- NASA MUREP Program (5)
- New York City (5)
- Nitrogen (5)
- Adsorption (4)
- Arsenic (4)
- Carbon (4)
- Climate (4)
- Climate Change (4)
- Geoscience Education (4)
- Groundwater (4)
- Group Learning (4)
- K9-16 STEM Outreach (4)
- Land cover (4)
- Plate tectonics (4)
- Precipitation (4)
- SAR (4)
- Virtual Platform (4)
- Publication Year
- Publication
- Publication Type
- File Type
Articles 151 - 180 of 315
Full-Text Articles in Earth Sciences
Carbonatites As A Record Of The Carbon Isotope Composition Of Large Igneous Province Outgassing, Ellen Gales
Carbonatites As A Record Of The Carbon Isotope Composition Of Large Igneous Province Outgassing, Ellen Gales
Dissertations and Theses
Large igneous province (LIP) eruptions have been linked in some cases to major perturbations of Earth’s carbon cycle. However, few observations directly constrain the isotopic composition of carbon released by LIP magmas because carbon isotopes fractionate during degassing, which hampers understanding of the relative roles of mantle versus crustal carbon reservoirs. Carbonatite magmatism associated with LIPs provides a unique window into the isotopic systematics of LIP carbon because the majority of carbon in carbonatites crystalizes rather than degassing. Here, we present new δ13C data for the Guli carbonatites in the Siberian Traps. In addition, we compile ~260 published …
Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi
Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi
Dissertations and Theses
Our preliminary survey showed that most of the recent flood-related studies did not formally explain the physical mechanisms of long-duration and large-peak flood events that can evoke substantial damages to properties and infrastructure systems. These studies also fell short of fully assessing the interactions of coupled ocean-atmosphere and land dynamics which are capable of forcing substantial changes to the flood attributes by governing the exceeding surface flow regimes and moisture source-sink relationships at the spatiotemporal scales important for risk management. This dissertation advances the understanding of the variability in flood duration, peak, volume, and timing at the regional to the …
Microbial Diversity In Urban Environments: Concern For Antibiotic Resistance, Ality Aghedo, Mangala Tawde, Nazrul I. Khandaker
Microbial Diversity In Urban Environments: Concern For Antibiotic Resistance, Ality Aghedo, Mangala Tawde, Nazrul I. Khandaker
Publications and Research
We are almost oblivious to the presence of microorganisms in our daily lives, but they exist and come into contact with us all the time. While some bacteria are harmless, and even beneficial, other bacteria can cause infections. A common treatment to bacterial infections is antibiotics and the success of an antibiotic depends on the resistance of the bacteria to the antibiotic. We conducted experiments to identify the types of bacteria that can be found on surfaces or within soil environments that come into contact with a vast number of people on a daily basis and how this can affect …
An Overview Of Smartwater Management System: Strategic Potential In Bangladesh, Muhammad Qumrul Hassan, Mir F. Karim, Nazrul I. Khandaker, Jowaher Raza
An Overview Of Smartwater Management System: Strategic Potential In Bangladesh, Muhammad Qumrul Hassan, Mir F. Karim, Nazrul I. Khandaker, Jowaher Raza
Publications and Research
Water loss management is becoming an increasingly important as supplies are stressed by population growth or water scarcity. A SmartWater system ensures optimum consumption and prediction of future water use. Bangladesh is one of the most vulnerable countries due to global climate change considering its rapid urbanization, inequitable land use, low income and greater reliance on climate sensitive sectors, particularly agriculture. Agricultural lands used for cropping and livestock rearing are more susceptible to degradation than non-agricultural lands. Most farmers irrigate through flooding, losing up to 75% of water to evaporation and creating a substantial drawdown of much needed water for …
Water Flow Net Characterization By Using A Tank Model: Preliminary Outcome, Jasmin Budhan, Nazrul I. Khandaker, Stanley Schleifer
Water Flow Net Characterization By Using A Tank Model: Preliminary Outcome, Jasmin Budhan, Nazrul I. Khandaker, Stanley Schleifer
Publications and Research
A model study was conducted to observe and characterize the flow of water through sandy soil. One of the most relevant tools used for characterizing groundwater flow is the flow net. Assuming that water is incompressible and there is zero volume change in the soil mass, it is known that the total rate of inflow is to equal the total rate of outflow. Thus, following the principle of flow continuity, we use the Laplace equation of continuity, to observe the concept of the flow net. Computing the flow through a miniature channel, we observed the total head difference from the …
Nasa Maa (Murep Aerospace Academy) Stem Project At York College: Ensuring Future Stem Pipeline, Nazrul I. Khandaker, Shuayb Siddique, Matthew Khargie, Brandon Dhanraj, Zachary A. Sanichar, Mildred M. Selby, Chabenauth Ramnauth, Theresa Deepan, Yougeeta Singh, Krishna Mahabir, Sashi Singh, Omadevi Singh
Nasa Maa (Murep Aerospace Academy) Stem Project At York College: Ensuring Future Stem Pipeline, Nazrul I. Khandaker, Shuayb Siddique, Matthew Khargie, Brandon Dhanraj, Zachary A. Sanichar, Mildred M. Selby, Chabenauth Ramnauth, Theresa Deepan, Yougeeta Singh, Krishna Mahabir, Sashi Singh, Omadevi Singh
Publications and Research
Our ongoing K1-12 NASA-supported STEM activities has served over 5000 children since 2015, largely from groups that are undeserved and underrepresented in the sciences. These STEM activities have been successfully delivered for several years and include earth science, meteorite geology, rocketry, aerodynamics, star gazing, EV3 Mindstorm robotics, basic coding exercises, wind tunnel, 3D-printing, etc., conducted largely through our present MAA (MUREP Aerospace Academy) Project. Corporate funding from the Con Edison and National Grid ensures additional STEM dissemination to the students during the summer operation. Significant positive component of the MAA program is the availability and willingness of the former student …
The Status Of Engineering Geology: Constraints On Infrastructure Development In Bangladesh, Mir Fazlul Karim, Muhammad Qumrul Hassan, Nazrul I. Khandaker, Masud Ahmed, Belal Ahmed Sayeed
The Status Of Engineering Geology: Constraints On Infrastructure Development In Bangladesh, Mir Fazlul Karim, Muhammad Qumrul Hassan, Nazrul I. Khandaker, Masud Ahmed, Belal Ahmed Sayeed
Publications and Research
In recent years, megacity Dhaka is known to have one of the fastest urban population growths in Bangladesh. The population in Dhaka and other megacities has increased from 7 to 50 million during the last four decades. The rapid rate of urban population growth, along with the extreme paucity of real-estate for new infrastructure development or upgrading existing facilities, is already exacerbating the situation for the city planners and exerting tremendous pressure to come-up with viable solutions. Although practice of engineering geology, geotechnical exploration, and testing exists in Bangladesh; the system has still yet to adopt controlled quality standards with …
The Challenges Of Geotechnical Exploration In Bangladesh For Sustainable Urban Development And Risk Reductions In Engineering Geology, Mir Fazul Karim, Nazrul I. Khandaker, Muhammad Qumrul Hasson, A.T.M. Shakhawat Hossain
The Challenges Of Geotechnical Exploration In Bangladesh For Sustainable Urban Development And Risk Reductions In Engineering Geology, Mir Fazul Karim, Nazrul I. Khandaker, Muhammad Qumrul Hasson, A.T.M. Shakhawat Hossain
Publications and Research
Bangladesh is a unique example of rapid urbanization where the urban population increased from 5 to 58 million in last four decades. Due to complex geology and active tectonic setting, the urban ground is impacted by fluvio-deltaic processes and regional seismicity. The densely populated cities of the country are facing risks from many natural hazards like floods, tidal surge, riverbank and coastal erosion, scour, landslides, soil collapse and foundation failures. Geologists anticipate severe seismic threats from yet-undefined tectonic structures and seek to determine their consequential geo-structural responses and conformance to the national building code. With rapid growth, demands on infrastructure …
Recruiting And Retaining K9–16 Students Through Field- And Laboratory - Based Geoscience Experiences, Nazrul I. Khandaker, Stanley Schleifer, Arif M. Sikder, Krishna Mahabir, Ality Aghedo, Charren Cabaroy, Mildred M. Selby, Gugu Ginindza, Leonardo Sanchez
Recruiting And Retaining K9–16 Students Through Field- And Laboratory - Based Geoscience Experiences, Nazrul I. Khandaker, Stanley Schleifer, Arif M. Sikder, Krishna Mahabir, Ality Aghedo, Charren Cabaroy, Mildred M. Selby, Gugu Ginindza, Leonardo Sanchez
Publications and Research
Since 2004, we have been directly involved with the GSA to provide access and opportunities for K9-16 students, particularly those interested in the broader aspects of geoscience-related topics, to present their field-and- laboratory based research outcomes at professional conferences and to learn from each other. So far, well-over 400 students from the U. S. and abroad have taken advantage of this opportunity and participated our topical sessions. It is quite gratifying to report that many of these students, as a result of their attendance at the GSA conference, felt a continuing need for exposure to high-level professional venues with effective …
Season-Ahead Forecasting Of Water Storage And Irrigation Requirements – An Application To The Southwest Monsoon In India, Arun Ravindranath, Naresh Devineni, Upmanu Lall, Paulina Concha Larrauri
Season-Ahead Forecasting Of Water Storage And Irrigation Requirements – An Application To The Southwest Monsoon In India, Arun Ravindranath, Naresh Devineni, Upmanu Lall, Paulina Concha Larrauri
Publications and Research
Water risk management is a ubiquitous challenge faced by stakeholders in the water or agricultural sector. We present a methodological framework for forecasting water storage requirements and present an application of this methodology to risk assessment in India. The application focused on forecasting crop water stress for potatoes grown during the monsoon season in the Satara district of Maharashtra. Pre-season large-scale climate predictors used to forecast water stress were selected based on an exhaustive search method that evaluates for highest ranked probability skill score and lowest root-mean-squared error in a leave-one-out cross-validation mode. Adaptive forecasts were made in the years …
Observed Differences Between Near-Surface Air And Skin Temperatures Using Satellite And Ground-Based Data, Satya Prakash, Farjana Shati, Hamidreza Norouzi, Reginald Blake
Observed Differences Between Near-Surface Air And Skin Temperatures Using Satellite And Ground-Based Data, Satya Prakash, Farjana Shati, Hamidreza Norouzi, Reginald Blake
Publications and Research
Accurate estimates of long-term land surface temperature (Ts) and near-surface air temperature (Ta) at finer spatio-temporal resolutions are crucial for surface energy budget studies, for environmental applications, for land surface model data assimilation, and for climate change assessment and its associated impacts. The Atmospheric Infrared Sounder (AIRS) and Moderate Resolution Imaging Spectroradiometer (MODIS) sensors onboard the Aqua satellite provide a unique opportunity to estimate both temperatures twice daily at the global scale. In this study, differences between Ta and Ts were assessed locally over regions of North America from 2009 to 2013 …
Regulation Of Dissolved Arsenic Using Zero-Valent Iron With Gypsum And Sulfate Reducing Bacteria: Laboratory Microcosm And Column Studies, Ying Liu
Dissertations, Theses, and Capstone Projects
Bench scale microcosm incubation was first conducted in two stages to examine the removal of arsenic (As) by zero-valent iron (ZVI) in the presence of sulfate reducing bacteria, gypsum as well as organic substrates under anaerobic condition. About 98% of dissolved As was removed from solution within 20 days with concurrent decrease of dissolved sulfate and growth of bacterial population. Mineralogy analysis using SEM-EDS found the formation of iron sulfide and Fourier-transformed infrared (FTIR) spectroscopy analysis indicates that some As is associated with pyrite. The main iron corrosion product was found as ferrihydrite with traces of lepidocrocite. Sequential leaching shows …
Investigation Of Biogeochemical Mechanisms Of Greenhouse Gas Production In The Urban Hudson River Estuary, Brian Alan Brigham
Investigation Of Biogeochemical Mechanisms Of Greenhouse Gas Production In The Urban Hudson River Estuary, Brian Alan Brigham
Dissertations, Theses, and Capstone Projects
Coastal megacities deposit significant amounts of carbon (C), nitrogen (N) and other pollutants into surrounding waters. These inputs, including wastewater and surface water runoff, may affect estuarine and adjacent wetland biogeochemical cycles, microbial production and ultimately greenhouse gas (GHG) efflux. In many megacities pollutant loading is typically greatest after periods of precipitation when the volume of wastewater and storm water runoff exceeds local sanitation capacity, resulting in the discharge of raw sewage into adjacent waters. These combined sewage overflow (CSO) events have received considerable attention primarily due to their potential impact on human health and eutrophication. However, whether these events …
Quantifying The Effects Of Wind Regimes And Temperature On Surface Melt Over The Antarctic Peninsula (1982–2017) Through Modeling, Remote Sensing And In-Situ Data, Rajashree Datta
Dissertations, Theses, and Capstone Projects
Surface melting over the Antarctic Peninsula (AP) plays a crucial role for the stability of ice shelves and dynamics of grounded ice, hence modulating the mass balance in a region of the world which is particularly sensitive to increasing surface temperatures. Understanding the processes that drive melting using surface energy and mass balance models is fundamental to improving estimates of current and future surface melting and associated sea level rise through ice-shelf collapse. This is even more important in view of the specific challenges presented by how circulation patterns over the topographically-complex Antarctic Peninsula, especially foehn winds, impact surface melt. …
Recent Trends In The Frequency And Duration Of Global Floods, Nasser Najibi, Naresh Devineni
Recent Trends In The Frequency And Duration Of Global Floods, Nasser Najibi, Naresh Devineni
Publications and Research
Frequency and duration of floods are analyzed using the global flood database of the Dartmouth Flood Observatory (DFO) to explore evidence of trends during 1985–2015 at global and latitudinal scales. Three classes of flood duration (i.e., short: 1–7, moderate: 8–20, and long: 21 days and above) are also considered for this analysis. The nonparametric Mann–Kendall trend analysis is used to evaluate three hypotheses addressing potential monotonic trends in the frequency of flood, moments of duration, and frequency of specific flood duration types. We also evaluated if trends could be related to large-scale atmospheric teleconnections using a generalized linear model framework. …
Hip Extensor Mechanics And The Evolution Of Walking And Climbing Capabilities In Humans, Apes, And Fossil Hominins, Elaine E. Kozma, Nicole M. Webb, William Harcourt-Smith, David A. Raichlen, Kristiaan D’Août, Mary H. Brown, Emma M. Finestone, Stephen R. Ross, Peter Aerts, Herman Pontzer
Hip Extensor Mechanics And The Evolution Of Walking And Climbing Capabilities In Humans, Apes, And Fossil Hominins, Elaine E. Kozma, Nicole M. Webb, William Harcourt-Smith, David A. Raichlen, Kristiaan D’Août, Mary H. Brown, Emma M. Finestone, Stephen R. Ross, Peter Aerts, Herman Pontzer
Publications and Research
The evolutionary emergence of humans’ remarkably economical walking gait remains a focus of research and debate, but experi- mentally validated approaches linking locomotor capability to postcranial anatomy are limited. In this study, we integrated 3D morphometrics of hominoid pelvic shape with experimental mea- surements of hip kinematics and kinetics during walking and climbing, hamstring activity, and passive range of hip extension in humans, apes, and other primates to assess arboreal–terrestrial trade-offs in ischium morphology among living taxa. We show that hamstring-powered hip extension during habitual walking and climbing in living apes and humans is strongly predicted, and likely constrained, by …
Estimation Of Consistent Global Microwave Land Surface Emissivity From Amsr-E And Amsr2 Observations, Satya Prakash, Hamidreza Norouzi, Marzi Azarderakhsh, Reginald Blake, Catherine Prigent, Reza Khanbilvardi
Estimation Of Consistent Global Microwave Land Surface Emissivity From Amsr-E And Amsr2 Observations, Satya Prakash, Hamidreza Norouzi, Marzi Azarderakhsh, Reginald Blake, Catherine Prigent, Reza Khanbilvardi
Publications and Research
Accurate estimation of passive microwave land surface emissivity (LSE) is crucial for numerical weather prediction model data assimilation, for microwave retrievals of land precipitation and atmospheric profiles, and for better understanding of land surface and sub-surface characteristics. In this study, global instantaneous LSE is estimated for the 9-year period from the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) and for the 5-year period from the Advanced Microwave Scanning Radiometer - 2 (AMSR2) sensors. Estimates of LSE from both sensors were obtained by using an updated algorithm that minimizes the discrepancy between the differences in penetration depths from microwave …
Bathymetry Data For Lakes Azuei And Enriquillo, Michael Piasecki, Mahrokh Moknatian
Bathymetry Data For Lakes Azuei And Enriquillo, Michael Piasecki, Mahrokh Moknatian
Publications and Research
This data set supports and forms the basis for the development of Digital Bathymetry Models (DBM) for Lakes Azuei (Haiti) and Enriquillo (Dominican Republic). Bathymetric Data is typically acquired using Sonar devices that measure the depth at specific points along a boat track and for which the longitude and latitude is recorded. From the resulting point cloud one develop a seamless representation of the floor of the lake on either a raster set (which is what we have done) or try to use a contour (vector representation) model in which the depth contours appear as polygons or -lines. The raw …
Evidence Of The 1762 Arakan And Prior Earthquakes In The Northern Sunda Subduction, Dhiman Ranjan Mondal
Evidence Of The 1762 Arakan And Prior Earthquakes In The Northern Sunda Subduction, Dhiman Ranjan Mondal
Dissertations, Theses, and Capstone Projects
The objective of this dissertation is to understand the seismic hazard associated with Arakan segment of the northern Sunda subduction along SE Bangladesh. In order to do that, it is necessary to document geologic evidence for the 1762 Arakan earthquake and prior events, to help estimate the recurrence interval (repeat time) for that earthquake. Historical records described that the 1762 earthquake caused extensive damage along the Arakan segment of the Sunda subduction system. But the geologic evidence for the earthquake farther north is necessary to better understand its associated seismic hazard to the densely populated nation of Bangladesh. This dissertation …
Aluminum-26: A Canonized Cosmochemical Conundrum, John Anton
Aluminum-26: A Canonized Cosmochemical Conundrum, John Anton
Dissertations, Theses, and Capstone Projects
This study focuses on the challenges associated with the historical development of the interpretative role of 26Al as both a thermodynamic contributor to planetesimal formation processes and an acutely precise chronometer of protoplanetary disk events. Conventional thought asserts that 26Mg concentrations can occur as isotopic excesses in meteorites and represent the daughter product of 26Al, a radioactive form of aluminum (t½ = ~0.73 ka). The greatest 26Mg concentrations generally occur in calcium aluminum inclusions (CAIs), meteoric constituents considered among the oldest known materials in the Solar System whose formation appear to predate the less refractory …
Evolution Of The Modern Baboon (Papio Hamadryas): A Reassessment Of The African Plio-Pleistocene Record, Christopher C. Gilbert, Stephen R. Frost, Kelsey D. Pugh, Monya Anderson, Eric Delson
Evolution Of The Modern Baboon (Papio Hamadryas): A Reassessment Of The African Plio-Pleistocene Record, Christopher C. Gilbert, Stephen R. Frost, Kelsey D. Pugh, Monya Anderson, Eric Delson
Publications and Research
Baboons ( Papio hamadryas) are among the most successful extant primates, with a minimum of six distinctive forms throughout Sub-Saharan Africa. However, their presence in the fossil record is unclear. Three early fossil taxa are generally recognized, all from South Africa: Papio izodi , Papio robinsoni and Papio angusticeps. Because of their derived appearance, P. angusticeps and P. robinsoni have sometimes been considered subspecies of P. hamadryas and have been used as biochronological markers for the Plio- Pleistocene hominin sites where they are found.
We reexamined fossil Papio forms from across Africa with an emphasis on their distinguishing features and …
Differentiation In Impact Melt Sheets As A Mechanism To Produce Evolved Magmas On Mars, Ari Koeppel
Differentiation In Impact Melt Sheets As A Mechanism To Produce Evolved Magmas On Mars, Ari Koeppel
Dissertations and Theses
Asteroid bombardment contributed to extensive melting and resurfacing of ancient (> 3 Ga) Mars, thereby influencing the early evolution of the Martian crust. However, information about how impact melting has altered Mars’ crustal petrology is limited. Evidence from some of the largest impact structures on Earth, such as Sudbury and Manicouagan, suggests that some impact melt sheets experience chemical differentiation. If these processes occur on Mars, we expect to observe differentiated igneous materials in some exhumed rock samples. Some rocks observed in Gale crater are enriched in alkalis (up to 14 wt% Na2O + K2O) and …
Supercycle In Great Earthquake Recurrence Along The Japan Trench Over The Last 4000 Years, Kazuko Usami, Ken Ikehara, Toshiya Kanamatsu, Cecilia M. Mchugh
Supercycle In Great Earthquake Recurrence Along The Japan Trench Over The Last 4000 Years, Kazuko Usami, Ken Ikehara, Toshiya Kanamatsu, Cecilia M. Mchugh
Publications and Research
On the landward slope of the Japan Trench, the mid-slope terrace (MST) is located at a depth of 4000–6000 m. Two piston cores from the MST were analyzed to assess the applicability of the MST for turbidite paleoseismology and to find out reliable recurrence record of the great earthquakes along the Japan Trench. The cores have preserved records of ~ 12 seismo-turbidites (event deposits) during the last 4000 years. In the upper parts of the two cores, only the following earthquakes (magnitude M ~ 8 and larger) were clearly recorded: the 2011 Tohoku, the 1896 Sanriku, the 1454 Kyotoku, and …
Convective Transport Of Tropical Marine Boundary Layer Species Into The Upper Troposphere And Relation To Species Lifetime: In Situ Measurements And Global Model Simulation, Sofia M. Chelpon
Dissertations and Theses
This study investigates the influence of tropical deep convection on distribution of trace gasses in the tropical upper troposphere (UT) using data from the Convective Transport of Active Species in the Tropics (CONTRAST) Experiment conducted over the tropical western Pacific during January and February of 2014. Fifty-five chemical species measured during the CONTRAST campaign are analyzed with lifetimes ranging from less than a day to several years. The vertical profiles of these species suggest that they fall into three main groups delineated by their lifetime: 1) very long-lived trace gases demonstrating a nearly constant vertical structure, 2) intermediate lifetime species …
The Sedimentary Imprint Of Pleistocene Glacio-Eustasy: Implications For Global Correlations Of Seismic Sequences, Cecilia M. Mchugh, Craig S. Fulthorpe, Koichi Hoyanagi, Peter Blum, Gregory S. Mountain, Kenneth G. Miller
The Sedimentary Imprint Of Pleistocene Glacio-Eustasy: Implications For Global Correlations Of Seismic Sequences, Cecilia M. Mchugh, Craig S. Fulthorpe, Koichi Hoyanagi, Peter Blum, Gregory S. Mountain, Kenneth G. Miller
Publications and Research
We evaluate lithofacies, chronology, and seismic sequences from the Canterbury Basin, New Zealand passive continental slope (Integrated Ocean Drilling Program [IODP] Expedition 317 Site U1352 and environs) and compare this with slope sequences from the New Jersey passive margin. Our goal is to understand continental slope sedimentation in response to glacio-eustasy and test the concepts of sequence stratigraphy. High-resolution geochemical elemental and lithostratigraphic analyses were calibrated to a chronology constructed from benthic foramininferal oxygen isotopes for the past ~1.8 m.y. We identify lithofacies successions by their unique geochemical and lithologic signature and correlate them with marine isotope stages (MIS) at …
River-Bed Armouring As A Granular Segregation Phenomenon, Behrooz Ferdowsi, Carlos P. Ortiz, Morgane Houssais, Douglas J. Jerolmack
River-Bed Armouring As A Granular Segregation Phenomenon, Behrooz Ferdowsi, Carlos P. Ortiz, Morgane Houssais, Douglas J. Jerolmack
Publications and Research
River bed-load transport is a kind of dense granular flow, and such flows are known to segregate grains. While gravel-river beds typically have an “armoured” layer of coarse grains on the surface, which acts to protect finer particles underneath from erosion, the contribution of granular physics to river-bed armouring has not yet been investigated. Here we examine these connections in a laboratory river with bimodal sediment size, by tracking the motion of particles from the surface to deep inside the bed, and find that armour develops by two distinct mechanisms. Bed-load transport in the near-surface layer drives rapid, shear ratedependent …
Experiential Learning Opportunity (Elo) And Utilization Of Field-And-Data- Based Information Obtained Through The Infusion Of Technology: Highlights On Nasa Stem And Earth Science Curricula, Nazrul I. Khandaker, Matthew Khargie, Shuayb Siddiqu, Sol De Leon, Katina Singh, Newrence Wills, Krishna Mahibar
Experiential Learning Opportunity (Elo) And Utilization Of Field-And-Data- Based Information Obtained Through The Infusion Of Technology: Highlights On Nasa Stem And Earth Science Curricula, Nazrul I. Khandaker, Matthew Khargie, Shuayb Siddiqu, Sol De Leon, Katina Singh, Newrence Wills, Krishna Mahibar
Publications and Research
There is a greater emphasis on hands-on involvement and critical thinking skills in the geosciences and other STEM fields to inspire and engage K- 16 students to value scientific content and enable them to discover the well-documented nature of the fundamental scientific principles needed to explain various earth science and other STEM-related core phenomena. NASA MAA curricula are ideal for engaging K1-16 students in this context, since grade-specific lesson plans open-up a plethora of pedagogically sound and relevant earth science activities. These include earth’s materials and properties, meteorites, robotics, hot air balloon, flight simulation, star gazing, material science, crystal growth, …
Raritan Formation (Upper Cretaceous), Long Island, New York: Sedimentological And Geochemical Assessment, Nazrul I. Khandaker, Arif Sikder, Stanley Schleifer, Xin-Chen Liu, Carlos E. Castano Londano, Joseph B. Mcgee Turner
Raritan Formation (Upper Cretaceous), Long Island, New York: Sedimentological And Geochemical Assessment, Nazrul I. Khandaker, Arif Sikder, Stanley Schleifer, Xin-Chen Liu, Carlos E. Castano Londano, Joseph B. Mcgee Turner
Publications and Research
The lithology of the Upper Cretaceous Raritan Formation (RF) consists of two members: an upper clay member (Raritan clay) and a lower unit, the Lloyd Sand Member. RF is unconformably overlain by upper Pleistocene glacial deposits. The RF consists of stratified white, light- to dark-gray, and red beds and lenses of clay, silt, and sand; lignite and pyrite are common. Variegated, thin to thickly-bedded Lloyd sandstone (LS) is considered to be one of the extensive regional aquifers in Long Island and interpreted to be nearshore, fluvio-deltaic deposit. Proximity to fluvial axes and active deltaic lobes plays an important role in …
Further Study Of Garnet Xenocrysts In New York City Migmatites, Stanley Schleifer, Nazrul I. Khandaker
Further Study Of Garnet Xenocrysts In New York City Migmatites, Stanley Schleifer, Nazrul I. Khandaker
Publications and Research
The authors have previously published an article at the 2004 Geological Society of America Annual Meeting, Petrogenetic Significance of Garnets in the Bedrock of New York City, in which they suggested that the garnet xenocrysts observed in the quartzofeldspathic zones of the migmatites, so frequently seen both at the surface, and below the surface pursuant to the construction of the Manhattan portion of New york City Water Tunnel #3, were a refractory residue of the anatectic melting of the immediately surrounding schistose bedrock. Although the relatively high melting point temperature of garnet compared to other minerals in the surrounding …
The Impact Of Climate Change On Biodiversity In Nepal: Current Knowledge, Lacunae, And Opportunities, Aishwarya Bhattacharjee, Jose D. Anadon, David L. Lohnman, Tenzing Doleck, Tarendra Lakhankar, Bharat Babu Shrestha, Praseed Thapa, Durga Devkota, Sundar Tiwari, Ajay Jha, Mohan Siwakoti, Naba R. Devkota, Pramod K. Jha, Nir Y. Krakauer
The Impact Of Climate Change On Biodiversity In Nepal: Current Knowledge, Lacunae, And Opportunities, Aishwarya Bhattacharjee, Jose D. Anadon, David L. Lohnman, Tenzing Doleck, Tarendra Lakhankar, Bharat Babu Shrestha, Praseed Thapa, Durga Devkota, Sundar Tiwari, Ajay Jha, Mohan Siwakoti, Naba R. Devkota, Pramod K. Jha, Nir Y. Krakauer
Publications and Research
Nepal has an extreme altitudinal range from 60–8850m with heterogeneous topography and distinct climatic zones. The country is considered a biodiversity hotspot, with nearly a quarter of the land area located in protected areas. Nepal and the surrounding Himalayan region are particularly vulnerable to climate change because of their abrupt ecological and climatic transitions. Tens of millions of people rely on the region’s ecosystem services, and observed and modeled warming trends predict increased climate extremes in the Himalayas. To study the ecological impacts of climate change in Nepal and inform adaptation planning, we review the literature on past, present, and …