[ Search | Reply | Next | Previous | Up ]
From: Stacie White
Date: 11/18/02
Time: 12:57:42 PM
Remote Name: 66.82.9.15
This is what my sphere partner and I came up with on the hydrosphere and hurricanes. I will post some casual chains by tomorrow night.
The Hydrosphere and Hurricanes Sphere Study 11/17/02
Hurricanes, fueled by the water over the oceans, are wild, ferocious, forces of energy that can destroy life and property in widespread areas. We have all heard at one time or another about the devastation of certain regions from strong hurricanes, such as Hurricane Camille in 1969 which had winds gusting from 200 mph; 143 people died and as the storm weakened and continued northward, another 113 died from floods and landslides in Mississippi and Alabama. Hurricane Hugo in 1989 had 150 mph winds; after crashing into the South Carolina coast it moved into North Carolina. The storm claimed 60 deaths in South and North Carolina. No one can forget the devastation that Hurricane Andrew caused in Florida and Louisiana; 40 deaths were caused from this Category 4 hurricane and an estimated $25 billion in damages to property. (Http://www.msnbc.com/modlues/slideshow/hurrican_990913/slideshow.asp) While hurricanes have and will continue to be wild forces of nature they can only be studied and learned from, but not stopped. The following sphere study will show evidence of the devastating effects of the hurricane to the hydrosphere with examples to help support the evidence. While all four spheres of the earth are affected by these strong storms more studies would be needed to prove that one sphere would be affected more so than another.
The Hydrosphere:
Water is a critical element that sustains life and drives a variety of environmental processes acting within the earth system (http://uwsp.edu/geo/faculty/geog101/modules/hydro.../) The hydrosphere is often called the “water sphere” as it includes all the earth’s water that is found in streams, lakes, the soil, groundwater, and in the air. The hydrosphere interacts with, and is influenced by, all the other earth’s spheres. Water is held in oceans, lakes, and streams at the surface of the earth. Water is found in vapor, liquid, and solid states in the atmosphere. The largest amount of water storage is in the oceans, which contain over 97% of the earth’s water. Most of this water is salt water. The average depth of the oceans is 3,794m (12,447 ft), more than five times the average height of the continents. (Http://encarta.msn.com/encnet/refpages/RefArticle.aspx?=761569459¶=6). Ice caps, like those found covering Antarctica, and glaciers that occupy high alpine locations compose a little less than 2% of all water found on Earth. Water beneath the surface comprises the next largest storage of water. Groundwater and soil water together make up about .5% of all water (by volume). (http://www.uwsp.edu/geo/faculty/ritter/geog101/modules/hydrosphere/hydrosphere.html) In Latin, hydro means water. Anything that scientists describe, when it comes to water, is a part of the hydrosphere. Water in it’s purest form is H20 and it is a small molecule that is very busy. (Http://www.geography4kids.com/files/water_hydrosphere.html)
Hurricanes:
Hurricanes are cyclones that develop over the warm tropical oceans and have sustained winds in excess of 64 knots (74 miles/hour). Hurricanes are “organized” storms of very low pressure. Like all areas of low pressure, they eventually move in response to upper level winds. Hurricanes are among the most destructive storms on Earth. They can cause havoc due to their strong winds, rains, tornadoes, the effects of very low air pressure, and resulting floods. (http://www.cotf.edu/ete/modules/sevweath/swintensity.html) Hurricanes are formed when large areas of the ocean become heated, and the air pressure over that area drops. This causes thunderstorms and strong surface winds. Cyclones develop over tropical or sub tropical waters (for example, in the Atlantic off the coast of Africa, or in the Pacific near the equator). As they travel long distances gathering energy from the ocean, they are likely to be classified as strong Tropical Cyclones. When the winds around the cyclone reach speeds greater than 74 mph, the cyclone is called a hurricane in the Atlantic and Northeastern Pacific, or a typhoon in the Pacific. Regardless of the region, there are common elements required for the storms to begin: warm ocean waters (over 79 degrees Fahrenheit), days of warm temperatures and high humidity, and light winds. Although these storms begin over 60% of the world’s tropical latitudes, they do not form in the region between about five degrees north and south of the Equator. This is due to the fact that at those latitudes, the Earth’s spin has little effect on organizing thunderstorm masses into whirling tropical storms. (http://www.usatoday.com/weather/hurricane/whclimo.htm) Once all the prerequisite conditions are in place, moisture from the warm waters evaporate bringing warm moist air high into the atmosphere providing the potential fuel for the hurricane. (http://kids.mtpe.hq.nasa.gov/archive/hurricane/index.html) Once there, winds begin to circle (counterclockwise north of the equator or clockwise south of the equator), gain strength, and move toward the center. The center of the storm, called the eye, is from 10 to 30 miles wide. Within the eye, the winds are calmer, the skies clear, and temperatures warm. It is created as some of the air from the top of the eye-wall moves inward and sinks. (http://kids.mtpe.hq.nasa.gov/archive/hurricane/creation.html; http://www.cotf.edu/ete/modules/sevweath/swwhatare.html) As more moist air is brought up from the warm waters, the storm begins to grow in size and strength perhaps up to 400 miles wide. The most violent activity within the storm takes place in the eye-wall, the area immediately around the eye. At the top of the eye-wall (up to 50,000 feet), the winds are propelled outward increasing the storm’s upward motion bringing more potential fuel for the storm in the form of warm moist air. (http://kids.mtpe.hq.nasa.gov/archive/hurricane/creation.html) Should one of the prerequisites no longer exist (i.e. the storm moves over land or cooler waters) the storm loses its power source and slowly weakens. http://www.cotf.edu/ete/modules/sevweath/swhoware.html) On average, each year, ten cyclones develop over the Atlantic Ocean, Caribbean Sea, or Gulf of Mexico. About six of these will strengthen enough to become hurricanes. (Http://kids.earth.nasa.gov/archive/hurricane/index.html)
Hurricanes are classified into different categories according to the Saffir-Simpson Scale. Developed in the 1970s to characterize the destructive potential of hurricanes, this scale includes maximum sustained wind speed, central pressure, storm-surge height, and coastal destruction potential. Storms are classified into one of five intensity categories from the least at Category 1 (minimal damage, occurring more frequently) to the greatest at Category 5 (catastrophic, likely to occur about once every hundred years). http://www.cotf.edu/ete/modules/sevweath/swintensity.html) These storms are capable of producing dangerous winds, torrential rains and flooding, all of which, may result in tremendous property damage and loss of life in coastal populations. One memorable storm was Hurricane Andrew which was responsible for 40 deaths and damages up to $25 billion dollars in Florida and Louisiana. Andrew caused violent winds and storm surges characteristic of a Category 4 hurricane in Dade County. (Http://www.msnbc.com/modules/slideshow/hurricane_990913/slideshow.asp). A hurricane requires an excessive amount of energy to swirl the winds around at speeds sometimes in excess 180 mph - an equivalent to frequent atomic explosions. It has been estimated that harnessing just one percent of the energy of a powerful hurricane could provide all the power, fuel, and heating needs of the United States for an entire year. (http://www.cotf.edu/ete/modules/sevweath/swwhatare.html)
For this particular sphere study, we will concentrate on the effects of a hurricane on the earth’s hydrosphere.
Event > Sphere Reactions:
E>H As the storm brings in increased wave and current action, salt water is forced into fresh water estuaries and bayous. (http://hurricanes.noaa.gov/prepare/surge.htm)
E>H Hurricanes will blow sea water into fresh water, such as lakes and streams, due to the extreme wind speed of the storm causing a disturbance in ph balance of the fresh water (of course, this would not be beneficial for any living thing that depended on that fresh water). Winds in a hurricane are at least 74 mph or higher so the wind can send the salt water anywhere. (Http://kids.earth.nasa.gov/archive/hurricane/index.html)
E>H Hurricanes will blow other contaminates, such as raw sewage, paper, anything not contained, in to sea water and fresh water streams and lakes or drinking water due to the excess amount of winds. At least 74 mph or higher of winds will send anything anywhere. These contaminates could cause water to be contaminated and unfit for human consumption. (Http://kids.earth.nasa.gov/archive/hurricane/index.html; http://encarta.msn.com/encnet/refpages/RefArticle.aspx?refid=761565992)
E>H As the storm approaches the coastline, the ocean levels rise about 15 feet or more. As a hurricane makes landfall, it brings with it a large dome of water often 50-100 miles wide called the storm surge. This surge is caused by strong onshore winds pushing the surface of the ocean ahead of the storm. This surge of water, topped by wind caused waves, causes considerable (perhaps the greatest) threat to life and property as it sweeps along the coastline. Combined with the occurrence of an astronomical high tide, this surge reaches its greatest height and can cause severe flooding of coastal areas. A very strong hurricane over shallow offshore water produces an even higher surge of ocean water as determined by the slope of the continental shelf. (http://kids.mtpe.hq.nasa.gov/archive/hurricane/damage.html; http://earthobservatory.nasa.gov/Library/Hurricanes/hurricanes_3.html; http://hurricanes.noaa.gov/prepare/surge.htm)
E>H Hurricanes can produce torrential rainfall in just a matter of minutes which can cause severe flooding of rivers, streams, streets, and towns, especially in low lying basin areas. The rainfall is so much that the already wet ground cannot absorb the volume that is accumulating and therefore causes the water to spill out and rise above normal water heights. (http://encarta.msn.com/encnet/refpages/RefArticle.aspx?refid=761565992) Along the edges of the storm are dense bands of thunderstorms spiraling slowly and often extending a few hundred miles from the center of the storm. These rain bands range in width from a few miles to tens of miles, and can be 50 to 300 miles long. (http://hurricanes.noaa.gov/prepare/structure.htm)These thunderstorms often produce widespread rainfall of 6-12 inches, heaviest usually about 6 hours before and 6 hours after making landfall. Slow moving storms often produce the greatest amounts of often torrential rains. In 1979, Tropical Storm Claudette dumped 45 inches of rain near Alvin, Texas. In North Carolina in 1999, Hurricane Dennis dropped 6 inches of rain followed by days of intermittent thunderstorms. Ten days later, Hurricane Floyd dumped 15-20 inches of rain across the state. Torrential rains can quickly cause rivers and creeks to rise and overflow their banks washing away roads, bridges, houses, fields, and livestock. (http://hurricanes.noaa.gov/prepare/rains.htm; http://earthobservatory.nasa.gov/Study/FloydIntro/)
E>H Flooding is often produced from the large amounts of rain dropped once the hurricane makes landfall. This can be intensified if the storm encounters another weather system. This occurred in 1969 when Hurricane Camille combined with an existing cold front in the mountains of central Virginia, dropping 30 inches of unexpected rain. (http://hurricanes.noaa.gov/prepare/rains.htm; http://earthobservatory.nasa.gov/Study/FloydIntro/)
E>H Large amounts of rain can occur more than 100 miles inland causing flash floods which wash away roads and bridges. (http://hurricanes.noaa.gov/prepare/rains.htm) In 1996, Typhoon Violet slammed into Tokyo, Japan, dropping 10 inches of rain in a 24 hour period resulting in flooding and landslides. (http://earthobservatory.nasa.gov/Study/ReckoningWinds/ ) In the year 2000, Typhoon Xangsane produced the worst floods Taiwan had had for 30 years. (http://earthobservatory.nasa.gov/Study/Seawinds/) In 1995, Hurricane Opal made landfall and dropped 15.45" on Ellyson, FL which washed away roads and caused flash flooding in the area. (Http://www.2010.atmos.uiuc.edu/(Gh)/guides/mtr/hurr/damg/flod.rsml)
E>H Torrential rains and flooding can contaminate water supplies for communities when sewage treatment plants are flooded. When this occurred in North Carolina in 1999, after the Tar River overflowed its banks, the water was deemed unusable for drinking or bathing fearing it harbored dangerously high levels of coliform bacteria from fecal sources. (http://earthobservatory.nasa.gov/Study/FloydIntro/)
E>H Large amounts of floods and rains from the storm can result in sediment, debris, and pollutants (including sewage and carcasses of dead animals) being washed into the coastal waters from the rivers. (http://earthobservatory.nasa.gov/Study/FloydIntro/) In 1999, Hurricane Floyd caused the mixing of the sediment washed into the coastal waters to be much deeper than normal, re-suspending sediments that had settled on the continental shelf nearly 200 meters below the surface. This was supported by images from remote sensing data such as the Sea-viewing Wide Field-of-view Sensor (SeaWiFS). (http://earthobservatory.nasa.gov/Study/FloydSediment/)
E>H Rivers can become polluted from the debris felled during the storm. There can be changes in levels of salt and oxygen. In the days following Hurricane Floyd, there were drops in levels of dissolved oxygen in the Pamlico River. This was attributed to outflow from swamps and decomposing organic matter in the flood runoff. Also, there were drops in salinity levels, which had been high due prevailing drought conditions. These changes were attributed to the massive outflow of the highly polluted freshwater. The dissolved oxygen levels recovered within weeks; however, it took months for the salinity levels to return to normal levels. (http://earthobservatory.nasa.gov/Study/FloydFear/fear.html)
Sphere >Event Reactions:
H>E As long as the hurricane is over the water and the water is heated up, already, this will cause a hurricane to gain strength and become stronger, and move faster. (Http://www.miamisci.org/hurricane/howhurrwork.html?310,177)
H>E Hurricanes require a continuous supply of water to replace what is lost in the form of raindrops. This is replenished by freshly evaporated water from the ocean that travels up the storm’s eyewall through convective activity and condenses in the air above the storm forming cloud droplets which are then encompassed as part of the thunderstorms. If the storm continues to move above the ocean’s surface encountering new sources of moist sea air, it continues to thrive. However, without this constant supply of evaporated water, the thunderstorms that make up a hurricane would eventually rain themselves dry and the low pressure system at the center the storm would die out and the hurricane would cease to exist! (http://earthobservatory.nasa.gov/cgi-in/texis/webinator/printall?/Study/HurricaneHeart/index.html)
H>E Any storm system that contained moisture (i.e. rain) that would encounter a hurricane, either on land or in the water, would only create a larger storm than would normally be. The already low pressure and heated warm water that helps to create the hurricane when combined with another storm could create a larger hurricane or more devastating torrential rains and flooding. (Http://www.miamiscie.org/hurricane/insideahurricane.html)
Summary:
Hurricanes are one of Mother Nature’s natural phenomena and can produce widespread damage to all 4 spheres of the Earth. The resulting damage could total billions of dollars or may even have the high price of death for some. Learning about Hurricanes, how and where they move can help to hopefully prevent possible deadly devastation. Hurricanes are monitored more effectively due to technological advances. Weather satellite images have improved our ability to detect and track severe weather. In 1999, NASA launched Quick Scatterometer (QuickSCAT) which uses specialized microwave radar to measure near surface wind speed and direction over the Earth’s oceans under all weather and cloud conditions greatly increasing available information. NASA’s Tropical Rainfall Measuring Mission (TRMM) was launched in 1997 with advanced computer instruments including precipitation radar, visible and infrared scanner, and lightning imaging sensors. Added to other weather observations and data, these data and images increase our ability to determine a storm’s location, direction, structure, and strength. Increased ability to understand the storm allows analysts time to warn the public in order to prepare for a storm’s arrival and potential threat. Hopefully, these technological advances will allow scientists to analyze the storms to determine the amount of energy released into the atmosphere and whether they affect global weather. (http://earthobservatory.nasa.gov/Library/Hurricanes/hurricanes_6.html; http://kids.mtpe.hq.nasa.gov/archive/hurricane/creation.html) Although hurricanes are wild and furious and cannot be tamed nor stopped, they can be monitored and studied. Costly damage to property and lives could be mitigated by thorough preparation if communication is maintained to the public and life-saving measures are taken to prevent even more disasters and death.
RESOURCES:
http://www.miamisci.org/hurricane/howhurrwork.html?310,177 http://msnbc.com/modules/slideshow/hurricane_990913/slideshow.asp http://ww2010.atmos.uniuc.edu/(Gh)/guides/mtr/hurr/home.rxml http://encarta.msn.com/encnet/refpages/RefArticle.aspx?refid=761569459¶=6) http://kids.earth.nasa.gov/archive/hurricane/index.html http://earthobservatory.nasa.gov/Library/Hurricanes/hurricanes_6.html http://kids.mtpe.hq.nasa.gov/archive/hurricane/creation.html http://www.uwsp.edu/geo/faculty/ritter/geog101/modules/hydrosphere/hydrosphere.html http://www.geography4kids.com/files/water_hydrosphere.html http://earthobservatory.nasa.gov/cgi- http://in/texis/webinator/printall?/Study/HurricaneHeart/index.html http://earthobservatory.nasa.gov/Study/FloydIntro/http://earthobservatory.nasa.gov/Study/FloydSediment/ http://earthobservatory.nasa.gov/Study/FloydFear/fear.html Http://www.2010.atmos.uiuc.edu/Gh)/guides/mtr/hurr/damg/flod.rsml http://earthobservatory.nasa.gov/Study/Seawinds/ http://earthobservatory.nasa.gov/Study/ReckoningWinds/ http://earthobservatory.nasa.gov/Study/ReckoningWinds/ http://hurricanes.noaa.gov/prepare/rains.htm http://hurricanes.noaa.gov/prepare/rains.htm http://hurricanes.noaa.gov/prepare/rains.htm http://hurricanes.noaa.gov/prepare/structure.htm http://kids.mtpe.hq.nasa.gov/archive/hurricane/damage.html http://earthobservatory.nasa.gov/Library/Hurricanes/hurricanes_3.html http://hurricanes.noaa.gov/prepare/surge.htm http://www.cotf.edu/ete/modules/sevweath/swwhatare.html http://www.cotf.edu/ete/modules/sevweath/swintensity.html http://kids.mtpe.hq.nasa.gov/archive/hurricane/creation.html http://www.cotf.edu/ete/modules/sevweath/swhoware.html http://www.usatoday.com/weather/hurricane/whclimo.htm