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Full-Text Articles in Physical Sciences and Mathematics

Late Pleistocene And Early Holocene Sea-Level History And Glacial Retreat Interpreted From Shell-Bearing Marine Deposits Of Southeastern Alaska, Usa, James F. Baichtal, Alia J. Lesnek, Risa J. Carlson, Nicholas S. Schmuck, Jane L. Smith, Dennis J. Landwehr, Jason P. Briner Nov 2021

Late Pleistocene And Early Holocene Sea-Level History And Glacial Retreat Interpreted From Shell-Bearing Marine Deposits Of Southeastern Alaska, Usa, James F. Baichtal, Alia J. Lesnek, Risa J. Carlson, Nicholas S. Schmuck, Jane L. Smith, Dennis J. Landwehr, Jason P. Briner

Publications and Research

We leverage a data set of >720 shell-bearing marine deposits throughout southeastern Alaska (USA) to develop updated relative sea-level curves that span the past ~14,000 yr. This data set includes site location, elevation, description when avail-able, and 436 14C ages, 45 of which are published here for the first time. Our sea-level curves suggest a peripheral forebulge developed west of the retreating Cordilleran Ice Sheet (CIS) margin between ca. 17,000 and 10,800 calibrated yr B.P. By 14,870 ± 630 to 12,820 ± 340 cal. yr B.P., CIS mar-gins had retreated from all of southeastern Alaska’s fjords, channels, and passages. At …


Tectonic And Geotechnical Review Of Bengal Basin For Seismic Risk Assessment In Bangladesh, Mir Fazlul Karim, Jnana Ranjan Kayal, Daya Shanker, Nazrul I. Khandaker, Arif M. Sikder, M Zillur Rahman, Muhammad Qumrul Hassan Oct 2021

Tectonic And Geotechnical Review Of Bengal Basin For Seismic Risk Assessment In Bangladesh, Mir Fazlul Karim, Jnana Ranjan Kayal, Daya Shanker, Nazrul I. Khandaker, Arif M. Sikder, M Zillur Rahman, Muhammad Qumrul Hassan

Publications and Research

Four major geotectonic provinces of the basin are recognized: 1) the continental slope to the west of the Hinge Zone, 2) the stable shelf, 3) the deep central trough (Sylhet-Hatiya) and 4) the Chittagong-Tripura fold belt to the east. The ~300 km long Dauki Fault demarcates the elevated Shillong Plateau, part of the Indian Shield to the north and the deep basin to the south. The basin experienced three strong to major intraplate earthquakes: a) 1885 Bengal earthquake (rev. Mw 6.8) close to the Hinge Zone, b) 1918 Srimangal earthquake (rev. Mw 7.1) on the Sylhet (trough) fault and c) …


Multi-Faceted Geoscience Research Using Open Access Resources: The Successful Participation Of K9-16 Students, Nazrul I. Khandaker, Noshin Sharmili, Omadevi Singh, Gurwinder Sahota, Sol De Leon, Matthew Khargie, Ali Zarine, Krishna Mahabir, Adacia Teemal, Mildred M. Selby Oct 2021

Multi-Faceted Geoscience Research Using Open Access Resources: The Successful Participation Of K9-16 Students, Nazrul I. Khandaker, Noshin Sharmili, Omadevi Singh, Gurwinder Sahota, Sol De Leon, Matthew Khargie, Ali Zarine, Krishna Mahabir, Adacia Teemal, Mildred M. Selby

Publications and Research

Students interested in geosciences, for the most part, missed out their traditional field- based research activities due to strict social distancing, travel restrictions and/or lacking financial support. An absence of physical laboratory opportunities forced students to choose topics deemed doable through online research. Available data from online sources on extreme weather related case studies, flooding, droughts, groundwater depletion in urban and suburban areas, coastal erosion rate, sealevel rise, landslides, earthquakes, volcanic eruptions, and atmospheric pollution became quite handy and lucrative. Readily available pertinent data sources enabled K9-16 students to conduct summer research at “stay home” situations. Selective peer mentoring was …


Addressing The Learning Loss During The Covid-19 Pandemic Through The Adaptation Of Virtual Platforms, Nazrul I. Khandaker, Anika Nawar Mayeesha, Violeta Escandon Correa, Toralv Munro, Andrew Singh, Matthew Khargie, Ality Aghedo, Jasmin Budhan, Krishna Mahabir, Belal A. Sayeed Oct 2021

Addressing The Learning Loss During The Covid-19 Pandemic Through The Adaptation Of Virtual Platforms, Nazrul I. Khandaker, Anika Nawar Mayeesha, Violeta Escandon Correa, Toralv Munro, Andrew Singh, Matthew Khargie, Ality Aghedo, Jasmin Budhan, Krishna Mahabir, Belal A. Sayeed

Publications and Research

The York College-hosted NASA MAA (MUREP AEROSPACE ACADEMY) has always played a pivotal role in minimizing the learning loss during the summer months, which was heightened during the pandemic. Support from AT&T, Con Edison and NASA enabled the MAA program at York College to offer a virtual STEM education with an earth science concentration to 1000 plus underserved K1-12 students from the community last summer, including 160 high school students. Two factors made this endeavor fruitful: allowing additional time to engage in STEM lessons and increasing self-motivation to successfully accomplish assigned tasks. Students built partnerships and resolved technical issues with …


Assessment Of The Impacts Of Urbanization On Land-Use And Land-Cover Changes Using Remote Sensing And Python At Gazipur District, Bangladesh, Atika Rahman Akji, Nowshin Ahsan Priyanka, Anwar Zahid, Muhammad Qumrul Hassan, Jowaher Raza, Nazrul I. Khandaker Oct 2021

Assessment Of The Impacts Of Urbanization On Land-Use And Land-Cover Changes Using Remote Sensing And Python At Gazipur District, Bangladesh, Atika Rahman Akji, Nowshin Ahsan Priyanka, Anwar Zahid, Muhammad Qumrul Hassan, Jowaher Raza, Nazrul I. Khandaker

Publications and Research

Urbanization has been the central demographic trend, not only in the Asia-Pacific region, but also for the entire world. Local geo-mapping is the vital tool for analyses of land-use and land-cover. This study attempts to classify land-use in unsupervised settings and create land-cover map by using open-source Landsat data integrated with GIS technologies and other ancillary resources. This work concentrates on Gazipur Sadar (an upazila or sub-district of the Gazipur District in central Bangladesh, part of the Dhaka Division) and Kaliakair, which are rapidly growing unplanned urban and industrial zones. The usage of python coding greatly assisted accomplishing the post-classification …


Statistical Analysis Of Groundwater Level Fluctuation Of The Urban And Peri-Urban Area Of Gazipur District, Bangladesh, Nowshin Ahsan Priyanka, Atika Rahman Akji, Anwar Zahid, Muhammad Qumrul Hassan, Jowaher Raza, Nazrul I. Khandaker Oct 2021

Statistical Analysis Of Groundwater Level Fluctuation Of The Urban And Peri-Urban Area Of Gazipur District, Bangladesh, Nowshin Ahsan Priyanka, Atika Rahman Akji, Anwar Zahid, Muhammad Qumrul Hassan, Jowaher Raza, Nazrul I. Khandaker

Publications and Research

Groundwater is the primary source for drinking, municipal, irrigation, and industrial water supply in Bangladesh. Due to unplanned urbanization and rapidly growing industries, the degradation situation has become perilous over time. Dhaka and its peri-urban regions are having drastic changes in groundwater (GW) levels. This work reviewed GW level fluctuation in the peri-urban area, which is now severely experiencing the detrimental impact of rapid urbanization and industrialization. Detail statistical investigation and Landsat image interpretation of the study area was conducted. Analysis and prediction of water level trends were conducted using variations of Mann Kendell tests. Gazipur Sadar (an upazila or …


Determination Of Sustainable Zones For Groundwater Abstraction From The Multi-Layered Aquifer System In The Bengal Basin, Bangladesh, Anwar Zahid, Muhammad Qumrul Hassan, Nazrul I. Khandaker Oct 2021

Determination Of Sustainable Zones For Groundwater Abstraction From The Multi-Layered Aquifer System In The Bengal Basin, Bangladesh, Anwar Zahid, Muhammad Qumrul Hassan, Nazrul I. Khandaker

Publications and Research

The use of deep groundwater (±300 m deep) is becoming an important issue in the Bengal Basin, due to both water quality problems and an acute shortage of available water in upper aquifers. In southeastern Bangladesh, multi-layered aquifer conditions exist with arsenic contamination at shallow depths, and high iron and brackish groundwater occurring mainly in the deeper layers. Many previous studies have offered explanations for the high concentrations of dissolved arsenic in groundwater - most of which proposed that the arsenic is derived from geo-genic sources and its release in groundwater is through natural processes, not the result of anthropogenic …


The Importance Of Monitoring To Assess The Impact Of Climate Change On Groundwater Resources In Bangladesh, Muhammad Qumrul Hassan, Anwar Zahid, Nazrul I. Khandaker Oct 2021

The Importance Of Monitoring To Assess The Impact Of Climate Change On Groundwater Resources In Bangladesh, Muhammad Qumrul Hassan, Anwar Zahid, Nazrul I. Khandaker

Publications and Research

Groundwater is the major source of fresh water across much of the world, but there has been very little study on the impacts of climate change on this precious and finite resource. Rising levels of greenhouse gases are likely to increase the global average surface temperature over the next 100 years, raise sea levels and reduce soil moisture. The amount of water stored in the soil is fundamentally important to agriculture and influences the rate of actual evaporation, groundwater recharge and runoff. Rising sea levels would cause the tidal saltwater wedge to intrude further upstream in rivers, with resulting changes …


Development Of Predictive Models For Water Budget Simulations Of Closed-Basin Lakes: Case Studies Of Lakes Azuei And Enriquillo On The Island Of Hispaniola, Mahrokh Moknatian, Michael Piasecki Oct 2021

Development Of Predictive Models For Water Budget Simulations Of Closed-Basin Lakes: Case Studies Of Lakes Azuei And Enriquillo On The Island Of Hispaniola, Mahrokh Moknatian, Michael Piasecki

Publications and Research

The historical water level fluctuations of the two neighboring Caribbean lakes of Azuei (LA) and Enriquillo (LE) on Hispaniola have shown random periods of synchronous and asynchronous behaviors, with both lakes exhibiting independent dynamics despite being exposed to the same climatic forces and being directly next to each other. This paper examines their systems' main drivers and constraints, which are used to develop numerical models for these two lakes. The water balance approach was employed to conceptually model the lakes on an interannual scale and examine the assumptions of surface and subsurface processes. These assumptions were made based on field …


Earth System Science, Karin A. Block Oct 2021

Earth System Science, Karin A. Block

Open Educational Resources

Syllabus for 4-credit introductory earth system science course covering three units: 1. The Solid Earth; 2. The Fluid Envelope; 3. Climate and Natural Resources. Format is lecture plus 3 hr lab.


Sorption Of Metals At The Barite (001)-Water Interface, Inva Braha Sep 2021

Sorption Of Metals At The Barite (001)-Water Interface, Inva Braha

Student Theses

Abstract

Ion desorption processes control the retention of ions, such as Pb2+, at barite surfaces, whereas ion adsorption processes are a likely initial step in the incorporation of divalent cations, such as Sr2+ and Pb2+, into barite. Based on previous studies on samples dominated by flat terraces with relatively few defects, Sr2+ and Pb2+ adsorb and incorporate at the barite (001)-water interface (Bracco et al., 2019; Bracco et al., 2020). Here, I measured how susceptible lead (Pb) is to desorption and the role surface variability plays in its sorption behavior. First, I measured …


Carbon And Nitrogen Dynamics Of A Lagoon Salt Marsh In Davenport, California, Mark D. Gormley Sep 2021

Carbon And Nitrogen Dynamics Of A Lagoon Salt Marsh In Davenport, California, Mark D. Gormley

Dissertations, Theses, and Capstone Projects

Wetlands are complex environments that play a critical role in regulating the global biogeochemical cycle of carbon (C) and nitrogen (N). Wetlands are critical contributors to global climate change and atmospheric chemistry since they store as much as 33% of the world’s soil organic carbon (SOC), release more than 20% of the atmospheric methane (CH4), and produce nitrous oxide (N2O), an extremely potent greenhouse gas (GHG). Despite the enormous radiative forcing potential of carbon dioxide (CO2), CH4 and N2O derived from wetlands, uncertainties over the rates of C sequestration and GHG …


Evaluation Of The Potential Of Automated Sem-Eds Analysis For The Discrimination Of Inorganic Soil Particles, Anna S. Duggar Sep 2021

Evaluation Of The Potential Of Automated Sem-Eds Analysis For The Discrimination Of Inorganic Soil Particles, Anna S. Duggar

Dissertations, Theses, and Capstone Projects

Soil, that complex mixture of minerals, organic particles, chemicals, and anthropogenic materials, is ubiquitous and easily transferred, which gives it forensic relevance. Forensic soil analysis has traditionally included the identification and comparison of both organic and inorganic components, the inorganic portion being most commonly examined by light microscopy and other instrumental techniques. Predominantly, the inorganic materials in soil are naturally-occurring minerals, contributed as grains from the surrounding bedrock, which gives a soil its regional character. That parent material then undergoes physical, chemical, and anthropogenic changes producing wide geographic variation within a single region. This variation forms the basis for potential …


Case 3847 – Simopithecus Oswaldi Andrews, 1916 (Currently Theropithecus Oswaldi; Mammalia, Primates, Cercopithecidae), Proposed Conservation By Reversal Of Precedence With Cynocephalus Atlanticus Thomas, 1884., Eric Delson, David M. Alba, Stephen R. Frost, Dagmawit Abebe Getahun, Christopher C. Gilbert Aug 2021

Case 3847 – Simopithecus Oswaldi Andrews, 1916 (Currently Theropithecus Oswaldi; Mammalia, Primates, Cercopithecidae), Proposed Conservation By Reversal Of Precedence With Cynocephalus Atlanticus Thomas, 1884., Eric Delson, David M. Alba, Stephen R. Frost, Dagmawit Abebe Getahun, Christopher C. Gilbert

Publications and Research

The purpose of this application, under Articles 23.9.3 and 81.1 of the Code, is to conserve the usage of the species-group name Simopithecus oswaldi Andrews, 1916 by giving it precedence over its senior subjective synonym Cynocephalus atlanticus Thomas, 1884. Theropithecus is a common to dominant member of the extinct primate community across Africa after 4 million years ago (Jablonski & Frost, 2010) and often co-occurred with extinct humans (Hominini); fossils are also known rarely across Eurasia (Roberts et al., 2014). Most fossil samples are currently included in Theropithecus oswaldi (Andrews, 1916), which is often divided into chrono-geographic subspecies. Cynocephalus atlanticus …


Rezina Shams – The First Known Woman Geologist From Dhaka University (Bangladesh) To Obtain A Phd, Nazrul I. Khandaker Jul 2021

Rezina Shams – The First Known Woman Geologist From Dhaka University (Bangladesh) To Obtain A Phd, Nazrul I. Khandaker

Publications and Research

Rezina Shams (Dhaka University geology graduate 1985; née Rezina Bashar) is the first known female geologist from Bangladesh to obtain a PhD in 1991 (University of Birmingham, UK). Rezina’s undergraduate and graduate education in geology at Dhaka University (DU) was at a time when only a handful of female students attended the program. Rezina’s debut into her geology career began with the Master Plan Organisation (MPO) and then the Bangladesh Atomic Energy Commission (1986). Rezina kept her aspirations alive, and eventually furthered her geoscience education to a PhD. Upon receiving a PhD in 1991 from the University of Birmingham under …


Quo Vadis Lakes Azuei And Enriquillo: A Future Outlook For Two Of The Caribbean Basin's Largest Lakes, Mahrokh Moknatian, Michael Piasecki Jul 2021

Quo Vadis Lakes Azuei And Enriquillo: A Future Outlook For Two Of The Caribbean Basin's Largest Lakes, Mahrokh Moknatian, Michael Piasecki

Publications and Research

Lakes Azuei (LA) and Enriquillo (LE) on Hispaniola Island started expanding in 2005 and continued to do so until 2016. After inundating large swaths of arable land, submerging a small community, and threatening to swallow a significant trade route between the Dominican Republic and Haiti; worries persisted at how far this seemingly unstoppable expansion would go. The paper outlines the approach to a look forward to answer this question vis-à-vis climate change scenarios developed by the Intergovernmental Panel on Climate Change (IPCC). It uses numerical representations of the two lakes, and it examines how the lakes might evolve, deploying three …


Geologist Syed Humayun Akhter Is Leading The Bangladesh Open University, Nazrul I. Khandaker Jul 2021

Geologist Syed Humayun Akhter Is Leading The Bangladesh Open University, Nazrul I. Khandaker

Publications and Research

No abstract provided.


Fingerprinting The Cretaceous-Paleogene Boundary Impact With Zn Isotopes, Ryan Mathur, Brandon Mahan, Marissa Spencer, Linda Godfrey, Neil Landman, Matthew Garb, D. Graham Pearson, Sheng-Ao Liu, Francisca E. Oboh-Ikuenobe Jul 2021

Fingerprinting The Cretaceous-Paleogene Boundary Impact With Zn Isotopes, Ryan Mathur, Brandon Mahan, Marissa Spencer, Linda Godfrey, Neil Landman, Matthew Garb, D. Graham Pearson, Sheng-Ao Liu, Francisca E. Oboh-Ikuenobe

Publications and Research

Numerous geochemical anomalies exist at the K-Pg boundary that indicate the addition of extraterrestrial materials; however, none fingerprint volatilization, a key process that occurs during large bolide impacts. Stable Zn isotopes are an exceptional indicator of volatilityrelated processes, where partial vaporization of Zn leaves the residuum enriched in its heavy isotopes. Here, we present Zn isotope data for sedimentary rock layers of the K-Pg boundary, which display heavier Zn isotope compositions and lower Zn concentrations relative to surrounding sedimentary rocks, the carbonate platform at the impact site, and most carbonaceous chondrites. Neither volcanic events nor secondary alteration during weathering and …


A Consistent Model Of Terrestrial Planet Magnetospheres And Rotations In Our Solar System, Fred J. Cadieu May 2021

A Consistent Model Of Terrestrial Planet Magnetospheres And Rotations In Our Solar System, Fred J. Cadieu

Publications and Research

The Sun comprises 99.9% of the solar system mass so it is expected that Sun terrestrial planet interactions can influence the motion as well as the rotation of the terrestrial planets.Gravity affects the planet orbital motions while the changing magnetic fields of the Sun can influence the planet rotations. Planets that manifest a magnetic field dominate any weaker magnetic fields from the Sun, but the rotation of terrestrial planets without a magnetic field interacts with the changing Sun’s field dependent on the electrical conductivity of the core region. It is determined that the average planet density becomes a useful quantity …


Dom Degradation By Light And Microbes Along The Yukon River‑Coastal Ocean Continuum, Brice K. Grunert, Maria Tzortziou, Patrick Neale, Alana Menendez, Peter Hernes May 2021

Dom Degradation By Light And Microbes Along The Yukon River‑Coastal Ocean Continuum, Brice K. Grunert, Maria Tzortziou, Patrick Neale, Alana Menendez, Peter Hernes

Publications and Research

The Arctic is experiencing rapid warming, resulting in fundamental shifts in hydrologic connectivity and carbon cycling. Dissolved organic matter (DOM) is a significant component of the Arctic and global carbon cycle, and significant perturbations to DOM cycling are expected with Arctic warming. The impact of photochemical and microbial degradation, and their interactive effects, on DOM composition and remineralization have been documented in Arctic soils and rivers. However, the role of microbes, sunlight and their interactions on Arctic DOM alteration and remineralization in the coastal ocean has not been considered, particularly during the spring freshet when DOM loads are high, photoexposure …


Flooding Effects On China And Indonesia, Junhao Tan, Yuxuan Zhao, Yujie Li, Denny Caisaguano, Tanvir Hossain, Allan Zhu, Abdou Bah May 2021

Flooding Effects On China And Indonesia, Junhao Tan, Yuxuan Zhao, Yujie Li, Denny Caisaguano, Tanvir Hossain, Allan Zhu, Abdou Bah

Publications and Research

As climate change continues affecting the world, the damages and the problems follow by the flooding in certain regions are increasing. The research will be focuses on the impact of flood on two counties. The causes of flooding, the damages of flooding, and the solution developed to prevent and protect the cities.


Frozen In Time: A Numerical Modeling Approach To The Study Of Ice Bearing Planetesimals Through Carbonaceous Chondrites, Jasmine M. Bayron Feb 2021

Frozen In Time: A Numerical Modeling Approach To The Study Of Ice Bearing Planetesimals Through Carbonaceous Chondrites, Jasmine M. Bayron

Dissertations, Theses, and Capstone Projects

Icy planetesimals are significant objects of study for meteoritics, planetary science, and astrobiology due to their connections to the origins of life and liquid water on Earth. An existing closed system aqueous alteration model was adapted to simulate several scenarios involving early Solar System geologic processes occurring in an icy planetesimal interior. The model described in this work has been developed not only to test the validity of constraints currently thought to apply to CM1 parent bodies, but to directly compare the implications of these constraints for the isotopic composition and the modal mineralogy of carbonaceous chondrites. Isotopic ratios of …


Microstructural Characteristics Of Deformed Quartz Under Non-Steady-State Conditions, Hamidreza Soleymani Feb 2021

Microstructural Characteristics Of Deformed Quartz Under Non-Steady-State Conditions, Hamidreza Soleymani

Dissertations, Theses, and Capstone Projects

Because of the long timescale of many geological processes (millions of years), it has been traditionally assumed that the existing forces acting on the rocks at deep crustal levels are in equilibrium (i.e., steady-state). An alternative assumption, however, suggests that rocks in the lower crust and upper mantle are continuously evolving and exchanging energy at various time scales. Under the latter assumption (i.e., non-steady-state), certain geologic systems may never attain equilibrium regardless of the length and the time scale of operating geologic events. These two “endpoint” assumptions suggest there is a wide range of geologically reasonable conditions under which rocks …


Geol 746: Groundwater Hydrology, Tim Eaton Jan 2021

Geol 746: Groundwater Hydrology, Tim Eaton

Open Educational Resources

No abstract provided.


Application Of The Revised Universal Soil Loss Equation To Develop A Management Plan In The Chittagong Hill Tracts Region Of Bangladesh, Nira Rahman Jan 2021

Application Of The Revised Universal Soil Loss Equation To Develop A Management Plan In The Chittagong Hill Tracts Region Of Bangladesh, Nira Rahman

Theses

Land degradation from soil erosion is a major issue in hilly areas of tropical regions such as the Chittagong Hill Tracts (CHT) of Bangladesh. The combination of an elevated topography, high-intensity storms that are further exacerbated by the impacts of climate change, and farming practices increase the susceptibility of the region to soil erosion. The Revised Universal Soil Loss Equation (RUSLE) was developed in the mid-latitude dry climate zone of the United States during the 1990s to assist soil conservationists in implementing farming strategies that would address soil loss. Since then, researchers employed remote sensing and geographic information systems (GIS) …


Analysis Of Uncertainty In Hydrometeorological Ensemble Forecasts, Carolien N. Mossel Jan 2021

Analysis Of Uncertainty In Hydrometeorological Ensemble Forecasts, Carolien N. Mossel

Dissertations and Theses

Ensemble hydrometeorological forecasting has great potential for improving flood predictions and use in water management systems, however, the amount of data used and created with an ensemble forecast requires a careful and intentional approach to understand how useful and skillful the forecast is. The NOAA National Water Model (NWM) was run using downscaled NOAA Global Ensemble Forecast System (GEFS) meteorological forcings for the 2016-2017 wet season (October-March) in California to create an 11-member hydrologic forecast ensemble. To evaluate the performance of these ensemble forecasts, we chose to study streamflow sites within Sonoma County, California, a rain-dominated region which includes the …


Long Term Nutrient And Chlorophyll A Dynamics Across Long Island Sound And Impacts On Dissolved Oxygen Conditions Within The Western Sound (1991-2019), Sherry Perreira Jan 2021

Long Term Nutrient And Chlorophyll A Dynamics Across Long Island Sound And Impacts On Dissolved Oxygen Conditions Within The Western Sound (1991-2019), Sherry Perreira

Dissertations and Theses

Nitrogen overload, eutrophication, and hypoxia have been challenging and persistent water quality problems in Long Island Sound (LIS) over the past decades with major impacts on commercial industries, ecology, and recreational activities in the region. Recognizing these problems, the EPA enforced three phases of the Clean Water Act (CWA) to reduce nitrogen loads in an effort to improve this important estuary. This study examines how nitrogen (NH3, NOx & TDN), chlorophyll a (CHLA), and dissolved oxygen (DO) concentrations changed in LIS over the past 30 years, in response to water quality regulations as well as changes in …


Temperature Variance Portends And Indicates The Extent Of Abrupt Climate Shifts, Christine Ramadhin, Chuixiang Yi, George Hendrey Jan 2021

Temperature Variance Portends And Indicates The Extent Of Abrupt Climate Shifts, Christine Ramadhin, Chuixiang Yi, George Hendrey

Publications and Research

Here, we show a discernable increase in temperature variance before a glacial termination by both the Ansari-Bradley test and the moving variance methods plus introduce the idea that there is a correlation between the peak variance and peak temperature increase. The behavior of temperature variance shows potential as a useful tool in analyzing time series data of Earth systems to assess the risk and extent of an upcoming abrupt climate transition.


Potential Solar Replacement Of Hydroelectricity To Reopen Rivers: Maine As A Case Example, Shailesh Sharma, John Waldman Jan 2021

Potential Solar Replacement Of Hydroelectricity To Reopen Rivers: Maine As A Case Example, Shailesh Sharma, John Waldman

Publications and Research

Hydroelectricity provides 6% of U.S. electrical power needs, but hydro-dams also cause environmental harm, including the retardation or complete blockage of spawning runs of anadromous fishes. To facilitate fish movements, engineered-fishways have long been used but many have performed poorly. Dam-removal is the most effective way of restoring dwindling migratory fish populations by allowing unrestricted pathways to their spawning areas and for the downstream migrations of post-spawning adults and juveniles. However, removals of hydro-dams result in a loss of electricity production. For the replacement of energy foregone from hydro-dam removals, various alternative energy installations are now feasible. We present one-to-one …


African Land Mammal Ages, John Van Couvering, Eric Delson Dec 2020

African Land Mammal Ages, John Van Couvering, Eric Delson

Publications and Research

We define 17 African land mammal ages, or AFLMAs, covering the Cenozoic record of the Afro-arabian continent, the planet’s second largest land mass. While fossiliferous deposits are absent on the eroded plateau of the continent’s interior, almost 800 fossil genera from over 350 locations have now been identified in coastal deposits, karst caves, and in the Neogene rift valleys. Given a well-developed geochronologic framework, together with continuing revision to the fossil record—both stimulated by the story of human evolution in Africa—and also to compensate for the variation in fossil ecosystems across such great distances, the AFLMAs are biochronological units defined …