he Nile is a majornorth-flowing river

in northeasternAfrica, and is the

longest river inAfrica and the dis-

puted longest river in the world. The Nile, which is about 6,650

km (4,130 mi) long, is an “interna-tional” river as its drainage basincovers 11 countries, namely, Tan-zania, Uganda, Rwanda, Burundi,the Democratic Republic of theCongo, Kenya, Ethiopia, Eritrea,South Sudan, Republic of the Su-dan and Egypt. In particular, theNile is the primary water source

of Egypt and Sudan.The river Nile has two major

tributaries, White Nile and BlueNile. White Nile is considered tobe the headwaters and primarystream of the Nile itself. Blue Nile,however, is the source of most ofthe water and silt.

White Nile is longer and risesin the Great Lakes region of cen-tral Africa, with the most distantsource still undetermined but lo-cated in either Rwanda or Burun-di. It flows north through Tanza-nia, Lake Victoria, Uganda andSouth Sudan. The Blue Nile beginsat Lake Tana in Ethiopia and flowsinto Sudan from the southeast. Thetwo rivers meet just north of theSudanese capital of Khartoum.

The northern section of the riv-er flows north almost entirelythrough the Sudanese desert toEgypt, then ends in a large deltaand flows into the MediterraneanSea.

Egyptian civilisation and Su-danese kingdoms have dependedon the river since ancient times.Most of the population and citiesof Egypt lie along those parts ofthe Nile valley north of Aswan, and

nearly all the cultural and histor-ical sites of Ancient Egypt arefound along river banks.

ot spring, also called a thermalspring, has a higher tempera-ture than the rest of the sur-rounding region. Most hotsprings discharge groundwa-

ter that is heated by shallow intrusions ofmagma (molten rock) in volcanic areas. Somethermal springs, however, are not related tovolcanic activity. In such cases, the water isheated by convective circulation: ground-water percolating downward reaches depthsof a kilometre or more where the tempera-ture of rocks is high because of the normaltemperature gradient of Earth’s crust – about30 °C per kilometre in the first 10 km.

SUM IT UP➤ Hot springs form when water deep below

Earth's surface is heated by rocks or othermeans, and rises to the Earth’s surface.➤ Mud pots form when hot spring watersmix with dirt and clay before they reach theEarth’s surface.➤ Extremophiles are tiny organisms thatthrive in hot springs and other places thatare inhospitable to most life on Earth.

So many extraordinary questions pop-up in our minds pertaining to the most ordinary occurrences inlife. Let us simplify the difficult processes and explain the how, why, when and where to you...

his forms agroup of coun-

tries where Ro-mance languages

such as Spanish,Portuguese, and French are pre-dominantly spoken; it is broad-er than the terms Ibero-Amer-ica or Hispanic America. The term “Latin America” wasfirst used in an 1856 conferencewith the title “Initiative of theAmerica. Idea for a FederalCongress of the Republics” bythe Chilean politician Fran-cisco Bilbao. The term was alsoused by Napolean III’s Frenchgovernment in the 1860s asAmérique latine to keep inmind French-speaking territo-ries in the Americas along withthe larger group of countrieswhere Spanish and Portugueselanguages prevailed, including

the Spanish-speaking portionsof the United States (South-western United Statesand Florida).Today, areas ofCanada andthe UnitedStates (withthe excep-tion of Puer-to Rico),where Span-ish, Por-tuguese andFrench are pre-dominant, are typi-cally not included in defini-tions of Latin America.

THE COUNTRIESLatin America is generally un-derstood to consist of the en-tire continent of South Amer-

ica in addition to Mexico, Cen-tral America, and the islands

of the Caribbean whoseinhabitants speak a

Romance lan-guage.

CULTUREEven since in-dependence,many of the

nations have ex-perienced simi-

lar trends, but thereare enormous differ-

ences. Not only do the peoplelive in independent units, butthe geography and climate oftheir countries vary immense-ly. The inhabitants’ culturalcharacteristics differ accord-ing to the constitution of theoccupants before the Iberianconquest, the timing and na-ture of European occupation,and their varying material en-dowments and economic roles.Since the Spanish and Por-tuguese element looms so largein the history of the region, itis sometimes proposed thatIberoamerica would be a betterterm than Latin America. Latinseems to suggest an equal im-portance of the French and Ital-ian contributions, which is farfrom being the case.

WHICH

T

WHATis a hot spring?

T

is the longest river in the world?

HOW DO HOTSPRINGS FORM?

Rain or ground water isheated when in contact

with rocks that have beenwarmed by magma. These

are formed near areas ofvolcanic activity. The heated

water becomes buoyant andviscous, and looks for cracks

and fissures to escape toEarth’s surface. Another kind of

hot spring forms when rainwater flows into the ground and

is heated by the radioactive decayof elements in the rocks that it

flows through. For each 1,000 feet,the water is heated an extra

10-150 F.

is Latin Americaso called?WHY

Photos: Getty images

H CAN IT BURN YOU? The hot springs have claimed a fewlives. The danger lies in the heat. Thepools can reach temperatures of upto 205 degrees Fahrenheit, enough tocause third-degree burns in seconds.

BLUE NILEBlue Nile springs from LakeTana in the Ethiopian Highlands.The Blue Nile flows about 1,400kilometre to Khartoum, whereBlue Nile and White Nile join toform the Nile. Ninety per centof the water and 96 per cent ofthe transported sediment car-ried by the Nile originates inEthiopia, with 59 per cent ofthe water from the Blue Nile(the rest being from the Tekezé,Atbarah, Sobat, and small tribu-taries). The flow of Blue Nilevaries considerably over itsyearly cycle and is the maincontributor to the large naturalvariation of the Nile flow.

WHAT ARE MUD POTS?When the water in a hot spring mixeswith dirt or clay before it reaches thesurface, the spring is called a mud pot.Mud pots are often highly acidic, bub-bling pools. When minerals in the mixturecause the mud to be brightly coloured, itis called a paint pot. They are found inthe United States and Europe.TOP HOT SPRINGS❚ Grand Prismatic Spring: Located in

Yellowstone National Park, it seems todisplay all the colours of the rainbow.❚ Blood Pond. Located in Japan, thewater is bright red in colour ❚ HammamDebagh: Located in Algeria, the waterfrom this spring cascades over a cliff.

are algal blooms? lgal blooms arelarge concen-trations of al-gae that growin the warm

waters of oceans, lakes andrivers. They are often harm-ful to marine life, and somebloom varieties can be toxicto humans. Blooms that growlarge are also proving to beharmful to economies thatrely on tourism. They canwash up ashore and formlarge piles on beaches. As wa-ter temperatures around theworld slowly creep higher,more and more algae bloomsare affecting wildlife and peo-ple negatively.

FACTS ABOUT ALGALBLOOMS

➤They tend to form in warmwaters such as the Gulf ofMexico during the summermonths.➤Some types are toxic to hu-mans, while others are not.➤ Algal blooms cause thesurrounding water to turndifferent shades of colour, de-pending on the plant.➤ Microscopic algae providethe fuel that drives marineand freshwater foodwebs,and via photosynthesis, theygobble up carbon dioxide tohelp counteract emissions,and provide us with oxygen.

A

WHAT CAUSESALGAL BLOOMS?An algal bloom is a phenom-enon that happens whenalgae plants (simple aquaticplants) multiply quickly.This can happen inboth fresh waterand salt watermarine envi-ronments.Depending onthe type of

algae involved, the water inthe surrounding area willturn a different colourbased on the pigmentationof the algae. Red tide andalgal blooms in general, are

affected by surround-ing atmospheric

conditions andwater temper-atures. Theyrequire a spe-cific tempera-

ture to thrive.

WHERE DO THEY OCCUR?❚ These phenomena are most common in places wherewater temperatures are warmer, such as the gulf coastsof Mississippi, Alabama and Florida during the summermonths. They also occur in the warm waters of theCaribbean, and can be found in East Asia, Africa, and asfar north as Canada. ❚ As average water temperaturesacross the US and Caribbean have been slowly rising overthe past few decades, scientists have noticed an increasein the rate of blooms in these and other areas, as well astheir severity.

RED TIDERed tide, which occurs inFlorida’s Gulf Coast, iscaused by toxic algaeknown as Karenia brevis.When consumed by birds,marine mammals and fish,the toxic algae can bedeadly. It can also harmpeople who eat contami-nated shellfish.

FUNFACT

There is only one nonLatin country in South

America, Suriname, whichis a Germanic country

as they speakDutch.

YELLOW NILE

Yellow Nile is a former tribu-tary that connected theOuaddaï Highlands of easternChad to the Nile River Valley8000 to 1000 BC. Its remainsare known as the Wadi Howar.The Wadi passes throughGharb Darfur near the north-ern border with Chad andmeets up with the Nile, nearthe southern point of theGreat Bend.

The only true wisdom is in knowing you know nothing.Socrates02 SCIENCE OF EVERYTHING