what is the Gulf of Mexico's "dead zone"? How is this formed? Is there a similar process/event in Lake Erie?
368092
The dead zone in the Gulf of Mexico is an area around the mouth of the Mississippi where there's a lot less sea life than in the rest of the Gulf Coast.  This is caused by over-fertilization in the Midwest.  Rain washes the fertilizer into the Mississippi and eventually into the Gulf.  All this fertilizer causes algae to grow wildly. As this algae dies and rots, the bacteria that decompose it use up most of the oxygen in the water, eventually 'suffocating' all the fish.\n\nI don't know if there's anything similar going in Lake Erie, but I think the one in the Gulf is the largest example of this problem anyone knows.  I can't think of any major rivers flowing through agricultural areas that empty into Lake Erie, so it seems like it might not have the same problem, but that's just a guess.
376142
Stream beds change due to sediment load that it carries & amount of water. They can meander or cut deeper into their bed. Oxbow lakes can form when meanders are cut off from the rest of the stream.\n\nRocks weather by wind & water. Self explanatory. Rock is removed by the wind & water and redeposited somewhere else as sediment.\n\nShorelines can either build up or erode depending on where they are located. Hurricanes can wash away shorelines or build them up too. Depending on how intense the storm is & amount of storm surge/ high tide or low tide, etc. Barrier islands are constantly changing. They move further inland during transgressions & move back out again during regressions. Hurricane can also close or open new inlets along barrier islands. Many of NC's barrier inlets have been closed & reopened by major hurricanes over the past couple hundred years.\n\nKarst topography. Areas w/ limestone bedrock will form sinkholes where the limestone is dissolved by naturally forming acids. This occurs especially where too much water is pumped out from these limestone aquifers. You can get sinkholes & sinkhole lakes/ponds. Lots of these in Florida.
277806
Geologists state that 200 million years ago a series of 'bucklings' caused by shifting tectonic plates created the Appalachian chain of mountains, which run from Tennessee across the Canadian Border. The Catskills are a portion of this plateau which simply "refused to go along." Their bedrock refused to "buckle". Instead this bedrock rose up by easy stages from the shallow sea in which its rocks (sedimentary?) had been formed (deposited?) from ancient mountains to the east. Raised high in the air the plateau became easy prey to the cutting action of the streams which carried off the plateau's rainwater. The plateau was carved up over 100's of thousands of years...the tough, hardest parts remained while the softer material was disposed of by various erosion techniques and actions including frost, water action and wind. Geologists explain the Catskills are simply a tough part of the Allegheny Plateau which the streams, even with the help of frost and gravity have not yet cut down to size. Over vast geologic time, of course, these forces will do away with the whole thing. In the meantime, scientifically speaking, the Catskills should be described as 'a maturely dissected part of the Allegheny Plateau".
1166752
From Wikipedia:\n\nMost geologists view crude oil, like coal and natural gas, as the product of compression and heating of ancient organic materials over geological time scales. According to this theory, it is formed from the decayed remains of prehistoric small marine animals and algae. (Terrestrial plants tend to form coal.) Over millennia this organic matter, mixed with mud, is buried under thick sedimentary layers of material. The resulting high levels of heat and pressure cause the remains to metamorphose, first into a waxy material known as kerogen, and then into liquid and gaseous hydrocarbons in a process known as catagenesis. Because hydrocarbons are less dense than the surrounding rock, these migrate upward through adjacent rock layers until they become trapped beneath impermeable rocks, within porous rocks called reservoirs. Concentration of hydrocarbons in a trap forms an oil field, from which the liquid can be extracted by drilling and pumping.\n\nGeologists also refer to the "oil window". This is the temperature range that oil forms in--below the minimum temperature oil does not form, and above the maximum temperature natural gas forms instead. Though this corresponds to different depths for different locations around the world, a 'typical' depth for the oil window might be 4 - 6 km. Note that oil may be trapped at much shallower depths, even if it is not formed there. Three conditions must be present for oil reservoirs to form: a rich source rock, a migration conduit, and a trap (seal) that concentrates the hydrocarbons.\n\nThe reactions that produce oil and natural gas are often modeled as first order breakdown reactions, where kerogen breaks down to oil and natural gas by a large set of parallel reactions, and oil eventually breaks down to natural gas by another set of reactions.
1144422
The Burmuda triangle is an area of the atlantic ocean that stretches from the eastern lower United States seaboard to the northwestern tip of South america and almost to Africa. Its all a bunch of BS! This particular area of the atlantic ocean is the largest trade route in the world! What do you think will happen here? Its like comparing the DanRyan expressway in Chicago to your average country road. Where will most accidents likely occur?
611576
Into the abyss of course........:)\n\n*runs to the blog to go copy her answer from there*\n\nLovely picture by the way, but it has scared me from ever boarding the Mayflower. Thank goodness I'll never have to. I would have looked horrendous in the pilgrim shoes anyway. But enough rambling......let me get to the question.\n\nThe ships would all fall into the abyss. What if....the fall was neverending? What if they just kept falling with no where to land? would the water keep running too? would it lead to another land? Is this where "neverland" is? Or do we fall and fall into a nothingness? Or will we fall and land on the River Styx? \n\nWe know the ocean water has to return other wise the earth would be drained and before long draught would be the next issue after global warming. So my thoughts are crazy but that the water falls and falls and falls until it hits a warp that sucks it back up and into the earth yet again similar to the way a fountain works. A never ending cycle. But if so........what could possibly be at the bottom of the abyss??? One shall never know. *sigh*
993995
I have lived in Florida for 22 years and the warmest I've seen it get is 91 degrees F.  It is possible that it could get a degree or 2 warmer than that, but it requires the right conditions of getting it up to that temp, for example, a long period of direct heating by the sun and next to no rainfall to run off into the Gulf to lower the temp near the coast. So basically an area of High pressure dominating the weather patterns and also the proximity to a warm current such as the Gulf Loop Current, the Florida Straights which in turn becomes the Gulf Stream.
395877
Yes, it's also called the Sea of Cortez.  Ya know that little strip of land that shoots out the west side of Mexico?  The water there is the gulf of California
1099047
In a way you are correct because both pressure and temperature are involved in the formation process. Oil would will not form unless the organic material it is made from is 'cooked'  at a temperature between 140 degrees F and about 250 degrees F. Below that temperature it never forms, and at the upper limit it forms natural gas. At even higher temperatures it decomposes releasing any hydrogen and oxygen and leaves behind only graphite, nearly pure carbon. This process is not similar to rotting which is biological, but is in fact a chemical change that can be reproduced in a laboratory. This is one reason that the abiogenic hypothesis of oil formation is not well-regarded among geologists- high temperatures of the deep crust would destroy hydrocarbons and change them to graphite. \n\nIt would be very misleading to describe the burial process that creates oil and gas as "earth collapsing in upon itself" though.  The process is very much a part of the rock cycle itself and is repeating over and over during geologic time. As mountains are uplifted they erode, and the resulting material is carried by rivers to the sea, where it deposits in deep piles (several miles) of sediment as river deltas. As the organic-rich rock like shale are buried deeper and deeper they experience higher pressure and are heated by the natural warmth of the deep earth. This cooks the organic material making oil or gas. Other types of source rock for oil are in limestone, which is created by living organisms like reefs, but the same burial and cooking process is required to make oil out of the organic material. \n\nSee my other answer at:\nhttp://answers.yahoo.com/question/index;_ylt=AnypfUEcztdBLvBgKdiqgY7sy6IX?qid=20060615215053AApCUl3\nor my older answer to this question at:\nhttp://answers.yahoo.com/question/;_ylt=AqkzP9amgCudYabOz20w2YIjzKIX?qid=1006022109950
40537
About 25 or 26 thousand feet in the Mariana's trench in the Pacific.  Depth varies greatly... Gulf of Mexico is around 11,000 at its deepest point South of Lousianna.  About 400 miles off the Florida coast, the Atlantic is around 16000 feet deep.  The caribbean varies but is generally very shallow, especially from Florida to Cuba and east to the Bahamas.  Many ships were lost in history because of the shoals (shallow areas).
1028302
The Dead Zone?\n\nWindfall?
447867
gulf of Mexico.  The total area of the Gulf of Mexico is approximately 615,000 mi² (1.6 million km²), the southern third of which lies within the tropics, and plunges to a depth of 2,080 fathoms (3804 m). This deepest part is Sigsbee Deep, an irregular trough more than 300 nautical miles (550 km) long, sometimes called the "Grand Canyon under the sea."
375342
The Gulf Stream is a strong warm ocean current, transporting as much heat as the annual output of 1 million power stations. It moves water at a rate of 30 million cubic meters per second off of Florida, increasing to 80 million cubic meters per second as it moves farther north. The volume of the Gulf Stream is far more water than all the water of all rivers that empty into the Atlantic combined (they barely total 0.6 million cubic meters per second.)\n\nHere's a cool heat image of the gulf stream (see URL below).
847104
I can see that you have never been to the Panama Canal and discovered that the Pacific Ocean is higher than the Gulf of Mexico...a sea level ditch would cause the Pacific Ocean to flow into the Gulf of Mexico until it had reached an equal hieght...flooding all cities along the Atlantic and Gulf coasts.
986662
The folks who identified the Gulf of Mexico as the spot where the huge impact occurred are correct.   The crater has been named Chicxulub, and it is huge--though it did not form the Gulf of Mexico--which existed before the meteor landed.  Website below gives additional information about the location of the site, and links to information about its structure, where some of  the ash from the explosion went, and so forth.\nSecond url links to geophysical survey showing bullseye gravity anomalies over proposed site.\nThere are some scientists who argue that the final,final bit of extinction of some index fossils that marks what scientists call the Cretaceous-Tertiary boundary (K-T boundary), actually occurred a little later than the big impact. The third website links you to some of that debate.
818715
any help?\nhttp://www.gdrc.org/uem/water/mexsaade.htm\nor:\nhttp://msucares.com/pubs/publications/p1939.htm\nor:\nhttp://www.ehponline.org/docs/2002/110-10/ss.html#diar\nor:\nhttp://www.uswaternews.com/archives/arcglobal/6mexfre.html\n\nhope something is useful!
1058011
I think that what you are asking about might be better called coastal deposition.\n\nOver the span of geologic time the sea level has changed dramatically. As the sea level has moved up and down over time the coastal erosion process has created continental shelves that are covered in deposits eroded from dry land around some continents. This process has also helped shape the coastlines of the continents. \n\nOne of the more spectacular examples of coastal deposition are river deltas. The sediment carried by the river is deposited as the flow of river water slows. This tends to sort the sediments according to the energy level of the water that is flowing into the open ocean. First larger grains like gravel and pebbles settle down, and as the river slows, sand, and finally clay size particles settle out of the water. Many river deltas have built up sediment deposits that are several miles thick and cover areas as large as some states. Most of southern Louisiana is a river delta deposit. \n\nAlong many coasts there is a predominant wind direction that helps to build coast long-shore currents. These currents move parallel to the coastline and will cause sediment accumulations (from rivers) such as sand bars and islands to slowly migrate in one direction. Much of the sand on beaches is actually slowly migrating along the shore. As heavier winter waves move the sand offshore, the sand also tends to move along the shore and sometimes temporarily moves back up onto the beach at a new location. \n\nAnother geologic process that is involved in coastal change is both uplift and subsidence. Uplift is taking place on some coasts due to tectonic plate motion. Other coasts are subsiding, or sinking, due to both faulting and slow compaction of underlying sediments. This sort of subsidence is taking place along the Gulf Coast of the US where there are large growth faults that parallel the coast that are sinking towards the Gulf. Sediment deposited thousands and millions of years ago is still settling in some areas and this leads to loss of coastal wetlands and rising local sea level. \n\nIn other areas coastlines are being changed by local erosion of uplifted sediments (e.g. California). Landslides carry hillsides down to the coastline. Another change in many coastlines is being caused by a geologic process called isostacy. As glaciers accumulated across North America during the last ice age, they weighed down that part of the earth's crust and caused it to sink into the asthenosphere. The glaciers melted long ago, but the areas that were covered by glaciers are still rising. This creates a sort of teeter-totter effect, where some coastlines like parts of the East Coast of the US and the Louisiana coast are sinking. \n\nInformation on isostatic rebound:\nhttp://www.homepage.montana.edu/~geol445/hyperglac/isostasy1/\n\nMississippi River Delta:\nhttp://www.lacoast.gov/geography/basins/mr/\n\nExplanation of long shore drift:\nhttp://www.cofc.edu/CGOInquiry/longshoredrift.htm\n\nGood explanation of barrier islands:\nhttp://www3.csc.noaa.gov/beachnourishment/html/geo/barrier.htm\n\nA very good illustration of differential erosion in a coastal setting:\nhttp://www.rgs.edu.sg/events/geotrip/stack.html\n\nUN Coastal Types:\nhttp://www.oceansatlas.com/servlet/CDSServlet?status=ND0yNzYwJmN0bl9pbmZvX3ZpZXdfc2l6ZT1jdG5faW5mb192aWV3X2Z1bGwmNj1lbiYzMz0qJjM3PWtvcw~~