THE HYDROSPHERE.

The Earth’s water.

Hydrosphere is the combination of all the waters to be found on Earth. It includes:

Marine waters (oceans and seas), represent about 97’5% of the Earth’s waters and covers about 70% of the Earth’s surface.

Continental waters, most of them are fresh waters and represent  a 2’5% of the Earth’s waters. Includes rives, lakes, glaciers and aquifers.

Marine waters.

We can distinguish two types of marine waters:

Oceans are large masses of salt water. There are five oceans in order of size are:the Pacific, the Atlantic, the Indian Ocean, the Arctic and the Antarctic.

Seas, are áreas of the oceans that:

-Are close to the coastline.

-Shallower than the rest of the ocean.

For historical or cultural reason have their own names.

The water of the oceans has two main characteristics:

1.It is salt water, has sodium chloride disolved in it.

2.It is constantly moving. Has several kind of movements:

-waves, the undulating movement on the sea’s surface caused by the wind.

-tides, the rise and fall of the sea level caused by the Moon.

-marine currents, movements of large masses of water through the oceans. 



Are caused by two factors:

1.  The difference of temperature and salt levels of the oceanic waters. 
2. The wind.

Can be:

• Warm and cold, depending on wheter the temperature of the water that flow through it is lower or higher than the temperature of the water surrounding it.
• Surface or deep-sea depending of its depth.

A message in a bottle found three years and 5.000 kilometres later.
Experiment about water temperature and salinity.

Continental waters:

Most of the continental waters are fresh waters. Among them we can distinguish several types:

• Glaciers, large acumulation of frozen water. Most of them are located in Greenland, the Antarctica and high mountains.Them have two main parts:

1. Cirque, a steep bowl-shaped depression which form the head of the glacier.
2. Tongue, a narrow extension of ice projecting from the glacier cirque.

• Rivers are continuous currents of water that flow along a course. Most of them begin as springs and are supplied by rainfall or melting snow. Can flow into the sea or another river. We can distinguish three parts in the course of a river:

1. Upper course, the river flows in the mountains. Here flows very fast.
2. Middle course, the river flows through flat lands. The speed of the current is slower and the current of the river bends, forming meanders. A meander, is a bend in the course of the river formed by the accumulation of sediments.
3. Lower course, the river flows into the sea.

Upper course.

Middle source.

Lower course

• Lakes, are acumulations of water in low-lying areas of the Earth's crust. The water is supplied by rainfalls or rivers. We can also distinguish:

1. Lagoons, small lakes.
2. Seas, huge lakes such as the Caspian Sea.

Caspian Sea, the largest lake in Earth.

• Aquifers, are subterranean reserves of water, formed by the infiltration of water from the Earth's surface.

The water cycle.

The water cycle is the state of permanent circulation of the Earth's water. Water in Earth appears in the three states: liquid, solid (ice) and gaseous  (water vapour).

The fundamental processes of this cycle are:

• Evaporation, the change of water from a liquid to a gas (water vapour). Solar energy causes the evaporation of the surface water of the oceans and continental waters (lakes, rivers, etc.). 

• Condensation: Water vapour rises, cools, condenses and form clouds which are transported by the wind.
• Precipitation is the fall of the water onto the Earth’s surface in the form of rain, snow or hail. Is caused by the condensation of the water inside the clouds. When the clouds go up, water vapour cools and little drops of water appears. This drops combine with one another and when they reach a diameter of 0.5 mm fall to the ground.

A part of this water falls again into the oceans, but another part falls on the Earth, of this:

• A part filters into the subsoil and forms aquifers (infiltration). Sometimes the water of the aquifers reaches the surface trough a spring.

Water spring.

• Other remains on the surface forming rivers and lakes.

Finallly, the rivers and the aquifers run into the oceans and the cycle stars again.

The water cycle is a constant and balanced process. The total amount of evaporation and precipitation are compesated and as a consequence the quantity of water on the planet remains constant.

Water cycle.

Water consumption. Note: 1 gallon=4 litters
Water scarcity

ACTIVITIES:

1. Fill the blank spaces with the correct words:

The oceanic waters has three kind of movements: ______, _____ and ______  _______. A _____ is

a _________  movement of the sea's _______ caused by the ____.The ____ are the change of the
____ _____ caused by the ___________ pull of the ____. The _____  ______ are the ________ of 

huge masses of _____ inside the oceans caused by the ____ and the differences of ________ and

_________ between the different parts of the oceanic waters.

2.Complete the diagram with the correct words.
 

You can find the answers here.

ACTIVITIES UNIT. 1. THE EARTH and UNIT 2. THE EARTH'S RELIEF. SOLUTIONS.

Solutions:
Activities "THE GEOGRAPHIC GRID".
1. A: Latitude 70º N, Longitude 150º W; B: Latitude 20º S, Longitude 130º W; C: Latitude 40º N, Longitude 20ºW; D: Latitude 70º N, Longitude 100ºE; E: Latitude 30ºS, Longitude 80º E.

2. UNIT 1. THE EATRH AND ITS REPRESENTATION

With an A	The envelope of gases surrounding the Earth.	Atmosphere
With a C	A system of projection that translates the meridians and parallels onto a cone. It is the most appropriate way to represent the mod-latitudes, between the tropics and the polar circles.	Conical projection
With a C	A projection system that translate the parallels and meridians onto a cylinder. It is the best method to represent the low latitudes between the equator and the tropics.	Cylindrical projection.
With a D	The time each morning at which daylight first begins. Sunrise.	Dawn
With an E	A line notionally drawn on the earth equidistant from the poles, dividing the earth into northern and southern hemispheres and constituting the parallel of latitude 0.	Equator
Contains an F	The different shapes that the surface of the Earth has adopted over millions of year, as a result of internal forces.	Relief
With a G	A coordinate system that allows us to find every location on the Earth by its latitude and longitude.	Geographic coordinates
With a G	A scale that use a graduated ruler to indicate the equivalent to ground distance.	Graphical scale
With a H	Half of the earth, usually as divided into northern and southern halves by the equator, or into western and eastern halves by an imaginary line passing through the poles.	Hemisphere
Contains an I	The time of year when the Sun´s rays fall perpendicular to one of tropics. A 24-hour night takes place in one of the poles while the other has a 24-hours day.	Solstice
Contains  a K	The darker stage of twilight, especially in the evening. To become or make dark or dusky.	Dusk
With an L	The distance, measured in degrees, from any given point to parallel 0º or the equator.	Latitude
With an L	A year, occurring once every four years, which has 366 days including 29 February as an intercalary day. It is due to the orbit movement.	Leap year
With a M	A representation of the spherical surface of the Earth, or a part of it, on a flat surface.	Map
With an M	Imaginary semicircles traced from pole to pole. We use them to measure the longitude.	Meridians
With an N	A scale that use a fraction to indicate the equivalent to ground distance. The numerator designates the distance on the map, and the denominator tells us its equivalent on the ground.	Numerical scale
With an O	The movement of the Earth around the sun.	Orbit
With a P	A celestial body moving in an elliptical orbit around a star.	Planet
With a P	A projection system that translates the meridians and parallels onto a plane that touches the Earth on one of the poles. It is the most appropriate method to represent the polar areas.	Projection onto a plane
With a P	Imaginary lines that encircle the Earth, perpendicular to its axis. We use them to measure the latitude.	Parallels
With an R	The turning of the Earth around its imaginary axis.	Rotation
With an S	The number or graphic that indicates the relation between a distance drawn on the map and the same distance on the ground.	Scale
With a T	Any of the 24 longitudinal divisions of the earth's surface in which a standard time is kept.	Time zone
With a T	A type of map that represents in detail the physical and human aspects of the territory: relief, water, flora, communication routes, land use etc.	Topographic map
With a T	A type of map that represents a specific geographical aspect such as climate, relief, population, etc.	Thematic map
Contains a  U	A distance, measured in degrees, from any given point to meridian 0º or Greenwich.	Longitude
Contains an X	The time of year when the Sun´s rays fall perpendicular to the equator. The Sun illuminates the North Pole and the South Pole for the same number of hours.	Equinox
Contains a Y	A sun with planets, asteroids, comets, etc. in orbit around it.	Solar system

Activity: EARTH'S LANDFORMS.

UNIT 1. THE RELIEF.

With an A	Huge extensións of flat terrain located between the continental shelfs with a depth of between 4. 000 and 5. 000 metres.	Abyssal plain
Contains  a B	Flat surfaces found along the sea shore, are formed by the acumulation of sediments.	Beach
With a C	An area where the coast juts into the sea or land surfaces that are partially surrounded by the sea.	Cape
With a C	elevated areas with a very steep side located on a coast.	Cliff
With a C	The exterior layer of the Earth, is made up of solid rock.	Crust
With a D	A coastal landform located at the mounth of a river, formed by the accumulation of sediments.	Delta
With an E	Sudden movements of the Earth’s crust caused by the clash of two tectonic plates.	Earthquake
Contains an F	A glacial valley which have been flooded by the sea.	Fjord
With a G	Areas where the sea is partially enclosed by  the Earth	Gulf
With a E	River valleys which have been flooded by the sea.	Estuary.
With a H	Consists of all the water in the surface of the Earth.	Hidrosphere
Contains an I	Is the extension of land which links the peninsula to the continent.	Ithsmus
With an L	The outer solid layer of the Earth, is made up of the crust and the upper part of the mantle.	Litosphere
With an L	A depression filled by water	Lake
With a M	Elevated landforms which have an altitude of more tan 600 metres and very steep slopes.	Mountain
With an M	Old mountains which have rounded forms.	Massif
Contains a N	A gentle slope that extends from the continents beneath the sea waters.	Continental shelf
With an O	The process that explain the apparition of mountains. It occurs in the area where two tectonic plates come into contact.	Orogenesis
With a P	extension of land surrounded by water on all sides except one.	Peninsula
With a P	Extensive áreas of flat or gently undulating land which are located at an altitude of less than 200 metres above sea level.	Plain
With a P	Elevated plains which are located at altitudes of more tan 200 metres above sea level.	Plateau
With an R	Large group of mountains.	Mountain Range
With an R	Underwater mountains systems of several thousands metres of height.	Oceanic Ridge
With a T	Narrow elongated drepressions which cut the abyssal plains	Oceanic Trench
With a T	Huge wave that appear as a consequence of a underwater earthquake.	Tsunami
With a S	Sharp decline between the continental shelf and the abyssal plain.	Continental Slope
With a V	Sunken area of terrain located between mountains or plateaus	Valley
With a V	ruptures in Earth’s crust through which magma are released onto Earth’s Surface	Volcano