Natural Springs
Getting to the Source of Springs
One of the most dynamic geological features of Kythera generally, and particularly the village of Karavas, is the large number of natural springs.
The three springs in central Karavas - at Keramari, Amir Ali, and Portakalia, run perpetually.
Under Modern Landscapes, Peter Trifyllis, has provided kythera-island.net with a photograph of running spring water at the spring at Amir Ali.
Under Vintage Portraits/People - Panagiota Morfi, has provided us with a picture of the spring at Mitata - in this case a picture from a past era.
The water from those springs is exceptionally beautiful to drink. As my parents have been fond of telling me throughout my lifetime - "then vluffi" - it doesn't matter how much you drink, the water never makes you "feel full."
It is important to try to understand how these springs may have come into existence.
Kevin Sparkman of FloridaSprings Organisation has kindly given us permission to utilise his explanation as to how the abundant springs in Florida, USA have evolved. Many of the evolutionary principles outlined on the FloridaSprings website
www.FloridaSprings.org
will pertain to the evolution of the many springs on Kythera, and in Karavas.
Water Cycles Around
The journey of water begins in the sky, where the state's abundant rainfall recharges the Floridan aquifer, our underground water source. Read below to learn about the water cycle and how it contributes to spring formation.
Rainfall
Rainfall is a function of various atmospheric and physical factors, and the most important of these are gravity and humidity. As the tiny water droplets within a cloud merge together into larger, heavier drops, they eventually overwhelm the relative level of atmospheric humidity that keeps them airborne. Relative humidity is a measurement of the amount of water the air can hold at a given temperature. Scientists have recently determined that once these drops reach a diameter of twenty millimeters, rain will begin to fall. Every day, over 150 billion gallons of rain falls in Florida, more than any other state in the nation except Louisiana.
Evaporation and Condensation
Water's journey through the water cycle begins with a process called evaporation whereby water stored in surface bodies of water like lakes, rivers and the ocean is converted into water vapor by the heat of the sun. Convection then draws this warmer, wetter air upwards where it comes into contact with cooler, high atmospheric air and eventually condenses back into tiny water droplets. Collectively, these tiny droplets are called clouds.
Transpiration
In addition to evaporation, a significant percentage of the water is released into the atmosphere by trees and plants in a process called transpiration. In order to facilitate photosynthesis, plants absorb water from the soil through their roots, a process that can also clean water by filtering out nutrients and pollution. They then transpire this water back into the atmosphere through their leaves and stems. About 70 percent of all rainfall returns to the atmosphere in the form of evaporation and transpiration.
Runoff
Rainfall that is not absorbed directly into the soil, through the roots and leaves of plants, or accumulated into existing bodies of water such as lakes or rivers is called surface, or stormwater runoff. In areas where the underlying geologic formation is impervious to water, as in the case of clay, runoff is a natural process, directing water in sheet flow, into lakes, rivers, wetlands, and the ocean. In Florida, where loose sandy soils and porous limestone bedrock are common, rainfall that reaches the surface of the earth usually soaks directly into the ground.
Percolation
Rainfall seeps underground through a process called percolation, whereby water travels downwards through the tiny spaces between rocks and soil particles, and within the "Swiss cheese" structure of the limestone. The water eventually saturates the underlying limestone in much the same way water fills the tiny holes of a sponge. It is this process of percolation that allows Florida's abundant rainfall to replenish the immense volumes of water flowing from the springs.
Rain Falls Again
Though the first step of water's journey to the springs begins in the sky, the water cycle itself is a never-ending process, and no single step is more important than any other. Evaporation, transpiration, condensation, rainfall, run-off, and percolation all play a critical part in ensuring that water is consistently available for both natural processes and human use.
From Aquifer to Spring
The source of our drinking water and the crystal clear water in springs is the Floridan Aquifer, nature's underground water storage system. Read below to learn about our underground water cooler.
Recharge Basin
Water begins its journey underground to the aquifer by a process known as recharge whereby rainfall seeps underground to infiltrate the limestone below. The overall land surface area where water seeps underground and contributes rainwater to a specific spring is called a spring's recharge basin. North-central Florida, where spring upwellings are most abundant, contains hundreds of recharge basins. Given their complex three-dimensional structure, recharge basins are determined through extensive scientific studies of local subsurface geology and groundwater flow.
Percolation
Percolation is the physical process by which rainwater falling within a given recharge basin slowly travels underground through the tiny spaces between rocks and soil particles. Florida's unconsolidated, sandy soils as well as the porous nature of the limestone aquifer itself provide the ideal conditions for unrestricted percolation. Yet, depending on the type of soil and the depth of the limestone aquifer, some areas allow water to percolate water underground faster than others, resulting in different recharge rates. Areas of high recharge occur in only 15 percent of the state, mostly in the sandy highlands of west and west-central Florida.
Speleogenesis
Speleogenesis is a big word that describes the formation of caves. In Florida, speleogenesis occurs underground through a simple chemical reaction. As rainwater falls through the atmosphere and percolates through the soil, it combines with carbon dioxide in the air and decaying vegetation to form a mild carbonic acid that slowly dissolves the limestone enlarging small cracks and pores. Over thousands of years, these small pores and cracks expand to become underground caves and caverns. Collectively, these interconnected caves are the pipes through which groundwater flows within the aquifer to the springs.
Groundwater Flow
Gravity is the major force in groundwater movement in the aquifer. Under natural conditions, groundwater moves "downhill" until it reaches the land surface at a spring or through a seep in a riverbed, lake or wetland. The speed with which water flows through the aquifer is also dependent upon the porosity and permeability of the limestone. In other words, water flows more quickly if the spaces or holes in the limestone are larger and if these spaces are closely connected to allow water to flow through.
Sinkholes
Sinkholes are depressions in the land caused by dissolution of the limestone near the surface or the collapse of an underground cave. Once these "windows" to the aquifer are open, they may provide direct access to the conduits through which water flows from the recharge basin to the springs themselves. As a result, they are one of the most common points of entry for cave divers seeking to explore and study the underground aquifer.
Spring Formation
Springs form where groundwater is forced up and onto the surface through openings in the ground. This is caused by the differences in the slope or "hydraulic gradient" in the aquifer. As rain falls and percolates underground, it exerts pressure on the water already in the aquifer, forcing some to the surface through natural openings. The highest concentration of springs in Florida lies in the north-central part of the state where the aquifer is closest to the surface. Springs are classified or categorized based on the amount water discharge. The largest springs like Wakulla and Silver Springs are classified as "magnitude 1" springs which means they each discharges more than 65 million gallons of water a day - the equivalent of about 1.3 million bathtubs full!
Spring Flow
The volume of water flowing from a spring is dependent upon a variety of factors: the water pressure in the aquifer beneath it, the number of caves leading to the spring vent or opening, and the size of the vent itself. Florida's springs are the largest by volume in the world, giving birth to and supporting entire river eco-systems like the Suwannee and the Santa Fe. Collectively, Florida's springs discharge over 19 billion gallons of freshwater each day.
The Journey of Water
Getting to the Source of Springs
which has been replicated as Text Only in this entry,
can be viewed as an interactive display at
www.FloridaSprings.org
The interactive presentation requires Macromedia's Flash 5 player or newer for your web browser. If you do not have the Flash player, you can click on the entry at the FloridaSprings website to download it.
