Feedback Loop of Plant Earth

The Hydrosphere not only supports life on this planet but depending on its concentrations and locations can have lasting effects on our climate. The Hydrocycle is an example of a natural feedback loop that occurs on this planet.  Clouds accumulating creates rain that is absorbed by the ground and sucked up by the plants who then return the water to the atmosphere. This happens through transevaporation in the form of water vapor which condenses in the atmosphere and creates another rain cloud. This is an example of a feedback loop, and when these loops are interrupted by humans and other occurances on Earth the loop can be broken and have lasting effects on the environment, climate and ecological habitats.

Oceans  are the main source of evaporation and percipitation in the hydrologic cycle. At the current trend oceans are becoming more acidic as a result of the large amounts of CO2 it is absorbing. Too much CO2 can cause other disturbances like acid rain which kill fauna. When plants die there is less evapotranspiration re-admitted into the atmosphere. As the land becomes barren of plants it also absorbs more of the sun’s rays drying the soil which can result in deforestation. 

Deforestation is also decreasing the amount of water vapor released by plants through evapotranspiratition. As humans eliminate large areas of vegetated land we are seeing effects to our climate and environment that could be irreversible. Plants in the Amazon rainforest store large amounts of carbon dioxide. When these forests are torn down the stored carbon is released increasing the already high carbon dioxide that stores and captures heat in the atmosphere. The heat then warms the barren land to higher temperatures creating a climate change.

                           

Water divergence or damming is causing the few natural lakes we have on Earth to dry up. Damming water increases the surface area of water thereby increasing the evaporation rate of the once flowing water source. Downstream environments loose their nutrients, dry up, and die altering the landscape. The Aral Sea has shrunk in the last decade. An irrigation project to feed water to cotton plantations has diminished the water table from the fourth largest lake to less than 10% of its natural size. Human activities like these are altering the environment unconditionally. The area is now seeing  a decrease in precipitation and increase in temperature range.

                                                

    

The Aral Sea story

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These three human driving forces are interrupting the Earth’s natural feedback loops while changing and warming our climates, and destroying and depreciating our water supply.  Without water there can not be life. Humans around the globe are already feeling the effects of the disruptance of the hydrological cycle and there are many more challenges ahead to be faced.

http://www.effects-of-deforestation.com/amazon-rainforest-deforestation.php

http://www.fao.org/ag/magazine/9809/spot2.htm

http://www.youtube.com/watch?feature=fvwp&v=Z0Pi61SyVSM&NR=1

http://www.globalchange.umich.edu/globalchange2/current/lectures/deforest/deforest.html

Earthquakes in California

Earthquakes are a bizare phenomenon that can be explained but predicting when they occur is still a puzzling concept.  The Earth is made up of differents layers. The layer which humans and earth processes have modified is the thin outer crust made up of rock materials. This crust is put together like a puzzle and the pieces are called plate tectonics. These plates are always and have always been continuously moving. 

When these puzzle pieces converge, diverge and slide past one another we experience the dreaded earthquake.

Underneath the crust is the mantle this is the second layer of Earth. The mantle has different layers to it but the one closest to the lithosphere, or crust, is the Asthenosphere a bendable molten mixture that the tectonic plates float on. The Asthenosphere is the driving force of the movement of the plates. Where these puzzle pieces meet are ridges that have new molten material that pushes up through the crust through convection and spreads out, called sea floor spreadin. When new material is added to the crust pressure builds along the edges of these puzzles pieces(tectonic plates) until the pressure is too much to take and energy is released in the form of an earthquake. 

           

One of the well known, earthquake prone areas of the United States is the San Andres Fault located in California. Fault lines are associated with plate boundaries. In the case of the San Andres Fault we see a Transfom boundary of the Pacific and North American plates. There are several types of boundries between plates with different characteristics and movement.  Transform Boundries are charaterized by their 

horizontal movement past one another and lateral displacement of Earth’s crust. The two plates slip past one another when the pressure is too intense for the Earth’s crust and therefore the Earth under our feet shifts in a violent movement and jolt.

                                                                                                                                                                                                                 Areal view of the San Andreas Fault

Earthquakes origin of movement is relatively shallow. The pressure is released at the focus point, and or the center of the fault’s motion. This focus sends shock waves further below the origin and above. The area directly above the focus on the Earth’s crust is the epicenter. It is here that the wave of released energy in the earths surface is felt.

http://pubs.usgs.gov/gip/earthq1/how.html 

http://latimesblogs.latimes.com/lanow/earthquakes/

http://geology.com/san-andreas-fault/