The Quasi-Biennial Oscillation is a regular variation of the winds that blow high above the equator. Strong winds in the stratosphere travel in a belt around the planet, and every 14 months or so, these winds completely change direction. This means a full cycle takes roughly 28 months, making it the most regular slow variation […]
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The Madden Julian Oscillation (MJO) is an equatorial travelling pattern of anomalous rainfall that is planetary in scale. The MJO can be defined as an eastward movement of clouds, rainfall, winds and pressure near the equator that typically recurs every 30 to 60 days. The MJO moves eastward at 5 meters per second across the
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The North Atlantic Oscillation (NAO) is one of the most prominent and recurrent patterns of atmospheric circulation variability. It dictates climate variability from the eastern seaboard of the United States to Siberia and from the Arctic to the subtropical Atlantic, especially during boreal winter, so variations in the NAO are important to society and for
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The name ‘ENSO’ is the close interaction between the atmosphere and ocean. It is an irregularly periodic variation in winds and sea-surface temperatures over the tropical eastern pacific ocean, affecting the climate of much of the tropics and subtropics. The warming phase of the sea temperature is known as El-Nino and the cooling phase is
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Global overturning circulation is responsible for the transport of carbon and heat among the ocean basins and between the ocean and the atmosphere. The GOC can be conceptualized primarily into two connected overturning as follows – These two circulation cells are interconnected via upwelling in the southern ocean where deep water are mixed in the
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Marine isotope stages (MIS), marine oxygen-isotope stages, or oxygen isotope stages (OIS) are alternating warm and cool periods in the Earth’s paleoclimate, deducted from oxygen isotope data derived from deep sea core samples. Working backwards from the present, MIS 1 in the scale, stages with even numbers have high levels of O18 and represents cold
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Sapropel is a term used in marine geology to describe dark-colored sediments that are rich in organic matter. Sapropels events occurs periodically (around each 21000yr) and are specific to the Mediterranean sea. Organic carbon concentration in sapropels commonly exceeds 2% in weight. Their occurrence has been found to be related of the Earth’s orbital parameter.
Method Measured parameter Used physical property Suitable deposits type Seismic Travel time of reflected & refracted waves Density and Elastic modeVelocity and Acoustic Coal, Oil, Gas, Groundwater, Layered sedimentary basin, Ni- Cu- PGE in volcanic basal flows Gravity Gravity(Variation in earth’s gravitational field) Density contrast between the surrounding and host rock Massive sulfides, Chromite, Ni-Cu-
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Type of deposits Pathfinder element Gold- Silver vein type, Gold- Silver- Cobalt- Copper- Zinc and complex sulfide ores As W- Be- Zn- Mo- Cu- Pb- Skarns,Sn- Ba veins B Cu- Pb- Zn- Silver & Complex sulfide deposits Hg, Zn Ba- Ag vein deposit, Porphyry Cu Mn Wolframite- Tin contact metamorphic deposits Mo Porphyry Cu, Barium-
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Dry-line is a boundary that separates a moist air mass from a dry air mass. Also called a “Dew point front” because shape changes in dew point temperature can be observed across a dry line. Drylines are most commonly found just east of the Rocky Mountains, separating a warm, moist air mass to the east
