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Articles 3961 - 3990 of 59510

Full-Text Articles in Earth Sciences

Mgrre_Geolog_Collections Robarts, Tryphena M 1 21147289980000, Mgrre Western Michigan University Apr 2025

Mgrre_Geolog_Collections Robarts, Tryphena M 1 21147289980000, Mgrre Western Michigan University

Geolographs

No abstract provided.


Mgrre_Geolog_Collections Jansma-Gordon-Altschul 1-26 21101307680000, Mgrre Western Michigan University Apr 2025

Mgrre_Geolog_Collections Jansma-Gordon-Altschul 1-26 21101307680000, Mgrre Western Michigan University

Geolographs

No abstract provided.


Mgrre_Geolog_Collections Coder, Russell 1-10 21105300220000, Mgrre Western Michigan University Apr 2025

Mgrre_Geolog_Collections Coder, Russell 1-10 21105300220000, Mgrre Western Michigan University

Geolographs

No abstract provided.


Mgrre_Geolog_Collections State Dover 1-27 21137311650000, Mgrre Western Michigan University Apr 2025

Mgrre_Geolog_Collections State Dover 1-27 21137311650000, Mgrre Western Michigan University

Geolographs

No abstract provided.


Mgrre_Geolog_Collections Krol, Wanda Et Al 1-12 21137309090000, Mgrre Western Michigan University Apr 2025

Mgrre_Geolog_Collections Krol, Wanda Et Al 1-12 21137309090000, Mgrre Western Michigan University

Geolographs

No abstract provided.


Mgrre_Geolog_Collections Allmand, Thomas & Johnson, Will Unit 1-24 21137300040000, Mgrre Western Michigan University Apr 2025

Mgrre_Geolog_Collections Allmand, Thomas & Johnson, Will Unit 1-24 21137300040000, Mgrre Western Michigan University

Geolographs

No abstract provided.


Mgrre_Geolog_Collections Hanson, Anna Et Al 1-28 21133314310000, Mgrre Western Michigan University Apr 2025

Mgrre_Geolog_Collections Hanson, Anna Et Al 1-28 21133314310000, Mgrre Western Michigan University

Geolographs

No abstract provided.


Mgrre_Geolog_Collections State Allis 2-35 21141483120000, Mgrre Western Michigan University Apr 2025

Mgrre_Geolog_Collections State Allis 2-35 21141483120000, Mgrre Western Michigan University

Geolographs

No abstract provided.


Mgrre_Geolog_Collections State Chester 2-22 21137297500000, Mgrre Western Michigan University Apr 2025

Mgrre_Geolog_Collections State Chester 2-22 21137297500000, Mgrre Western Michigan University

Geolographs

No abstract provided.


Mgrre_Geolog_Collections Song Of The Morning Ranch 1-19 21137286560000, Mgrre Western Michigan University Apr 2025

Mgrre_Geolog_Collections Song Of The Morning Ranch 1-19 21137286560000, Mgrre Western Michigan University

Geolographs

No abstract provided.


Mgrre_Geolog_Collections Koronka, A 1-4 21137307730000, Mgrre Western Michigan University Apr 2025

Mgrre_Geolog_Collections Koronka, A 1-4 21137307730000, Mgrre Western Michigan University

Geolographs

No abstract provided.


Mgrre_Geolog_Collections Sobota, Thomas P & Rose M 1-25 21101318990000, Mgrre Western Michigan University Apr 2025

Mgrre_Geolog_Collections Sobota, Thomas P & Rose M 1-25 21101318990000, Mgrre Western Michigan University

Geolographs

No abstract provided.


The Formation Of Glacier Dirt Cones, Ryan M. Strickland, Matthew D. Covington Apr 2025

The Formation Of Glacier Dirt Cones, Ryan M. Strickland, Matthew D. Covington

Geosciences Faculty Publications and Presentations

Glacier dirt cones are meter-scale cones of ice covered with sediment and rock. The cones develop through a process known as differential melt, whereby ice underlying thick debris melts more slowly than bare ice. We report observations of dirt cones on the Kuskulana Glacier, Alaska and develop a model that simulates the growth of dirt cones from debris-filled pits in the ice. With this model, we vary ice melt rates, hillslope debris diffusion rates and pit geometry. Cone heights scale with the square root of debris volume and growth occurs in three distinct stages: emergence, flux-controlled growth and melt-controlled growth. …


Inconsistencies With The Drumian Carbon Isotope Excursion (Dice) In West-Central Utah, Michelle Norman Apr 2025

Inconsistencies With The Drumian Carbon Isotope Excursion (Dice) In West-Central Utah, Michelle Norman

Student Research Symposium

Geologic Setting

  • During the Cambrian Period (539-485.4Ma), the western US was submerged by a shallow ocean
  • Carbon cycle fluctuations in stable carbon were preserved in marine sediments
  • One such period of geologic time, the Drumian Age (500Ma), is defined by the first appearance of a deepwater trilobite, P. atavus, in west-central Utah
  • Researchers have hypothesized we can find Drumian-aged rocks without the fossils using carbon cycle fluctuations preserved in limestone
  • the Drumian Carbon Isotope Excursion (DICE) is defined as a -2.5‰ fluctuation in global carbon-bearing rocks



Earthquakes In Creeping Fault Zones? Mineralogic And Grain Size Controls On Frictional Behavior, Ainsley Macdonald Apr 2025

Earthquakes In Creeping Fault Zones? Mineralogic And Grain Size Controls On Frictional Behavior, Ainsley Macdonald

Student Research Symposium

1. Motivation

  • Faults can creep or be locked to produce earthquakes.

  • This behavior may be influenced by minerology and grain size

  • Serpentine minerals and clay are known to promote creep along faults

  • Does mineralogy promote creep along the Bartlett Springs Fault, CA?


Grassland For Our World, F Riveros Apr 2025

Grassland For Our World, F Riveros

IGC Proceedings (1977-2023)

The present-day role of grasslands and fodder is reviewed with respect agriculture, animal production and environmental concerns. The world 's grazing lands are a finite resource nnd, overall, are being badly mnnaEed; in most developing countries action is required now, before it is too lnte. They will continue to be a major source of animal feed for the foreseeable future; encroachment from cropping will con


Human Impact On Terrestrial Ecosytems- What We Know And What We Are Doing About It, H A. Mooney Apr 2025

Human Impact On Terrestrial Ecosytems- What We Know And What We Are Doing About It, H A. Mooney

IGC Proceedings (1977-2023)

At present the impact of humankind on the Barth System is substantial mul will become greater as we continue to add over 80 million people to the global population each year. Collectively the human species utilises over a third of the total fresh water that is available, as well as an equivalent amount of tho total terrestrial productivity. Possil energy is being consumed at a prodigious rnte and fuels, among other things, over a half a billion vehicles. To support the large human population the Earth has been greatly reconfigured with much of the land utilised for grazing and agriculture. …


Grasslands For Sustainable Ecosystems, Malcolm Hadley Apr 2025

Grasslands For Sustainable Ecosystems, Malcolm Hadley

IGC Proceedings (1977-2023)

Grasslnnds present many advantages for examining issues related to sustainability. Grasslands include planted pastures as well as a variety of natural rangelands in situations ranging from semi-arid to subhumid. Diversity is also reflected in the spectrum of grassland users and uses, for example, nomadic pastoralism, extensive ranches, intensive pastures, wildlife tourism, game hunting. And in terms of sustainability of resource management, grasslands encompass a wide range of contrasting situations and conflicts in resource use. Heavy grazing pressure associated with increasing human populations in certain tropical savannas, the implications of rural depopulation to traditional pasture management in alpine regions, and the …


Red Clover Hybrid Ryegrass Associations Results Obtained From 1984 To 1987 In Four French Regions, C Pfitzenmeyer, C Longueval Apr 2025

Red Clover Hybrid Ryegrass Associations Results Obtained From 1984 To 1987 In Four French Regions, C Pfitzenmeyer, C Longueval

IGC Proceedings (1977-2023)

In France, red clover is often grown in association with a grass in order, if not to increase the yield of forage, at least to improve its quality by having a larger protein content in the harvested product. Among the grass species associated to red clover, Italian ryegrass, too aggressive a competitor, is replaced more and more by hybrid ryegrass. The aims of the present work were the following

1% to obtain quantitative references on the behaviour o[ hybrid ryegrass/red clover associations in four contrasting regions of France ;

2% to check that the presence of clover, through the transfer …


Potentials Of Summer Fodders Under Intensive Cropping System In India, M S. Tiwana, Thakur Singh Apr 2025

Potentials Of Summer Fodders Under Intensive Cropping System In India, M S. Tiwana, Thakur Singh

IGC Proceedings (1977-2023)

One of the reasons for low milk production in India is the non-availability of good quality fodders in sufficient quantity. Therefore, it is necessary to bridge the gap of this acute short­age of fodder for increasing the milk production. There seems to be no possibility of increasing area under fodders and the only alternative looks to be the ulilization of vacant land (70 days) after harvesting wheat and before the sowing of main summer season crops. However, the growing of these crops may have some effect on the yield of succeeding crops by depleting or replenishing the nutrient status of …


Competitive Effects On Production Of Lolium Perenne L. And Trifolium Alexandrinum L. In Mixture And Mono-Culture, M S. Tiwana, K P. Puri, I S. Thind Apr 2025

Competitive Effects On Production Of Lolium Perenne L. And Trifolium Alexandrinum L. In Mixture And Mono-Culture, M S. Tiwana, K P. Puri, I S. Thind

IGC Proceedings (1977-2023)

Berscem (Trifolium alexandrinum L.) is grown as a fodder crop by every farmer of north India. Though it is a very good multi-cul legume fodder, yet its dry matter percentage is low which indirectly affects the total dry matter production over a period of 6 to 7 months. Presently no suitable multicut grass for the same period is available which may be grown separately or in mixture with berseem to produce high dry matter yield. The first successful planting of ryegrass in research trials was made in 1976 (Tiwana and Puri, 1984) in India. After that, we became interested …


Herbage Yield Of Annual Ryegrass (Lolium Multiflorium Lam.) And Common Vetch (Vicia Sativa L.) At Different Seeding Rates, M A. Jimenez, O L. Gallegos, M.J L. Castrellon Apr 2025

Herbage Yield Of Annual Ryegrass (Lolium Multiflorium Lam.) And Common Vetch (Vicia Sativa L.) At Different Seeding Rates, M A. Jimenez, O L. Gallegos, M.J L. Castrellon

IGC Proceedings (1977-2023)

Most of the dairy farms in the Central Valley of Mexico have alfalfa and corn silage as major forages. Winters are mild, how­ever, yield of alfalfa is reduced and no corn can be grown. For­age crops as oats, annual ryegrass and common vetch have been grown successfully to supply winter forage (Avendano, 1978; Victoria, 1981). Annual rycgrass generally outyields oats, but a high input of nitrogen is required by annual rye grass (Ciane, 1978). The high cost of N fertilizers prevents their use and cheaper N sources should be sought. Legumes as common vetch grown with annual ryegrass can be …


Performance Of White Clover Cultivars In Mixtures With Orchardgrass In Atlantic Canada, Joanna Fraser, H T. Kunelius Apr 2025

Performance Of White Clover Cultivars In Mixtures With Orchardgrass In Atlantic Canada, Joanna Fraser, H T. Kunelius

IGC Proceedings (1977-2023)

The climate in the Atlantic Provinces of Canada is ideally suited to pasture production, with up to seven months of grow­ing season in some areas. Moreover, many of the soils are too shallow to support deep-rooted and highly valued forages such as alfalfa (Medicago sativa L.) and corn (Zea mays L.). How­ever, the main limiting factor to pasture production occurs in spring where there are frequent freeze-thaw cycles, which reduce the dependability of snow cover for insulation, and this results in winter injury (Dzikowski et al., 1984). The interest in white clover (Trifolium repens L.) as a …


Comparison Of Ryegrass-White Clover And Competitive Interactions In New Zealand And Wales, W Harris, I Rhodes Apr 2025

Comparison Of Ryegrass-White Clover And Competitive Interactions In New Zealand And Wales, W Harris, I Rhodes

IGC Proceedings (1977-2023)

New Zealand and Wales have temperate climates suitable for ryegrass (Lolium species) and white clover (Trifolium repens) pasture. However, pasture management in New Zealand and Wales in fundamentally different. New Zealand pastures are grazed all year, whereas in Wales pastures are mostly not grazed in winter. Moreover New Zealand pastures mostly rely on nitrogen fixed by legumes, whereas nitrogen fertiliser is com­monly applied to Welsh pastures. To consider the basis of differences of pasture management in New Zealand and Wales, data from field experiments at Aberystwyth, Wales (Lat. 52°25'N) and Palmerston North, New Zealand (Lat. 40°20'S) are …


Forage Contribution Of Overseeded Cool-Season Clovers, G D. Mooso Apr 2025

Forage Contribution Of Overseeded Cool-Season Clovers, G D. Mooso

IGC Proceedings (1977-2023)

Warm-season perennial grasses are the foundation of pasture systems in the southeastern U.S. Though well adapted, these species require significant amounts of nitrogen (N) fertilizers to maintain forage production. Nitrogen fertilizers are widely used to improve the yield and quality of grass pastures because it was less expensive and easier to manage than grass-legume mixtures. Cool-season clovers overseeded into dormant peren­nial warm-season swards offer a practical method to extend the grazing season and improve forage quality while capitalizing on the ability of inoculated clovers to supply nitrogen to pro­duction systems thus decreasing production costs (Burton, 1976 ; Hoveland et al., …


Effect Of Irrigation On Vegetation Succession And Forage Regerneration, Fu Jing-Yan Apr 2025

Effect Of Irrigation On Vegetation Succession And Forage Regerneration, Fu Jing-Yan

IGC Proceedings (1977-2023)

No abstract provided.


Reponse Du Brome Cathartique A L’Irrigation Premiers Resultats, C Longueval Apr 2025

Reponse Du Brome Cathartique A L’Irrigation Premiers Resultats, C Longueval

IGC Proceedings (1977-2023)

L'interet de J'irrigation des graminees prairiales est unc ques­tion souvent debattue dans le sud de la France ou la secheresse estivalc ct frequemment automnale limite considerablement la production de fourrage vert durant cette deuxiemc moitie de l'annee. Dans la region toulousaine, les travaux de l'INRA a Tou­louse (Marty et al., 1977) ct de la Compagnic d'Amenagemenl des Coteaux de Gascogne ont montre, pour la fetuque et le dac­tyle notamment, que si !'irrigation pcrrnet de doubler la pro­duction estivale et automnale. le niveau attcint sans restriction hydrique reste globalement rr{odcstc puisque inferieur a 5 t/ha M.S. a partir du debut de …


Drought Stress And Alfalfa Production In A Mediterranean Environment, T Kipnis, I Vaisman, I Granoth Apr 2025

Drought Stress And Alfalfa Production In A Mediterranean Environment, T Kipnis, I Vaisman, I Granoth

IGC Proceedings (1977-2023)

Many experimental results have shown a close relationship between total dry matter (DM) yield of alfalfa and annual evapotranspiration (ET). However, this relationship may differ from harvest to harvest (Metochis and Orphanos, 1981), indicating that water use efficiency (WUE) may vary during the growing season, particulary as it is adversely affected by high temperature (Sammis, 1981). Water for irrigating alfalfa is often scarce during the dry Mediterranean summer in Israel. Under such conditions, water is withheld for approximately two months, at a relatively advanced stage of maturity, and the crop is allowed to go to seed, after which irrigation is …


On The Cultivation And Utilization Of Floret Silvergrass (Miscanthus Floridulus) In The Southern Area Of China, Zhu Bangchang Apr 2025

On The Cultivation And Utilization Of Floret Silvergrass (Miscanthus Floridulus) In The Southern Area Of China, Zhu Bangchang

IGC Proceedings (1977-2023)

The plant genus Miscanthus (silvergrass) includes eight species and one variety in China. In the tropical and subtropi­cal area of south China, the silvergrass distributed widely includes the following seven species : Floret silvergrass ( Miscanthus floridulus), Chinese silvergrass ( M. sinensis), Sugary silvergrass ( M. sacchariflorus), Short-hair silvergrass ( M. brevipilus j, Eulalia silver grass ( M. eulalioides), Szechuan silvcrgrass ( M. szechuanensis), Nepal silvergrass ( M. nepalen�� sis). One of them, Floret silvergrass, is the widest in distri­bution and the highest in economical value, and plays a most important role in …


Continuous Machine Line For Grassland Management On Slopes In Czechoslovakia, L Gonda, S Likavsky Apr 2025

Continuous Machine Line For Grassland Management On Slopes In Czechoslovakia, L Gonda, S Likavsky

IGC Proceedings (1977-2023)

Permanent grass covers in Czechoslovakia are to a great extent spread in sloping and rolling countryside. From the total area presenting 1,672 thousand hectares, 240 thousand ha are stretched on slopes with a gradient of 16 to 22 degrees. Research has shown that from 35 to 48 per cent of these pieces of land arc of size less than 10 ha and there are 75 per cent of intensive pastures with size smaller than 6 ha in typical moun­tainous regions of Czechoslovakia. Mechanization of grass picking on slopes is effected by speci­fic features predetermined by geographical conditions and requirements of …