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Sea Level Changes, Intertropical Convergence Zone, Thunderstorms, Tornados and Hurricanes

1. What effects cause changes in sea level? On what time scales do they act?
2. What is the intertropical convergence zone (ITCZ)?
3. What are the characteristics of a thunderstorm, a tornado, and a hurricane?

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1. What effects cause changes in sea level? On what time scales do they act?

The two most significant sources of changes in sea level are glaciations and glacial isostacy. Glaciation causes the volume of ice near the poles to fluctuate over time, subsequently causing water to be taken away or added to the world's oceans (Chappel and Lambeck, 2001). This can lead to sea-level oscillation of up to 200 meters (Chappel and Lambeck, 2001). Within the past 18,000 years, sea level has been rising in response to the melting of glacial ice and potentially global warming. This is mainly from melting ice from the Laurentian and Scandinavian ice sheets in Northern Canada. It is hypothesized that the rise in sea level was not uniform, and instead Is characterized by 2 minor and 2 major pulses of meltwater (Chappel and Lambeck, 2001). Glaciation is the fastest process involved in sea level rise, causing a 1-15 mm/ yr rise or decline.

Glacial Isostacy is when the shelf and margin rise/subside after ice loading, causing a rebound effect. Eustacy is the opposite, when ice loading during a glaciation causes land shelves to sink, leading to a rise in sea level relative to the continental crust. This tends to add or remove water at a rate of 1-5 mm/year, so it is slightly slower than glaciations but still highly significant (Chappel and Lambeck, 2001). Lithospheric depression of hundreds of meters takes place beneath large ice sheets due to the static weight of the ice mass. The excess loading causes elastic and plastic deformation of the ...

Solution Summary

The expert examines sea level changes and intertropical convergence zones. The characteristics of a thunderstorm, a tornado and a hurricane are defined.