The Indian Ocean is the third largest of the world’s oceanic divisions, covering 70,560,000 km².
It is bounded by Asia on the north, on the west by Africa, on the east by Australia, and on the
south by the Southern Ocean or, depending on definition, by Antarctica.
QUICK FACTS ABOUT THE INDIAN OCEAN
 The Indian Ocean is the third largest ocean in the world, encompassing about 20% of
water on the Earth’s surface.
 Many major rivers flow into the Indian Ocean, including the Zambezi, Jubba, Shatt alArab, Indus, Ganges-Brahmaputra, Godavari, Krishna, Narmada, and Irrawaddy.
 The currents in the Indian Ocean are mainly controlled by the monsoon.
 The Indian Ocean is the youngest of the major oceans on Earth.
 There are only two trenches in the entire Indian Ocean – the Java Trench and the Makran
Trench.
 The sea lanes within the Indian Ocean are extremely important for trade, as it provides
major sea routes that connect the Middle East, Africa, East Asia, Europe, and the
Americas.
 The Indian Ocean covers about 27.2 million square miles and is the warmest ocean on
Earth.
HISTORY OF THE INDIAN OCEAN
 The Indian Ocean opened up around 156 million years ago when Africa separated from
the supercontinent, Gondwana. From there, the Indian subcontinent broke away from the
Australia-Antarctica subcontinent between 135-125 million years ago.
 The first person to cross the Indian Ocean was a Greek man by the name of Eudoxus of
Cyzicus in the 2nd or 1st century BCE. It was also during this time that trade relations
developed between the Middle East and India.
 Historically important trading ports include ports in Durban, Richards Bay, Kolkata,
Chennai, Mumbai, Melbourne, Jakarta, and Colombo.
 The Indian Ocean came to prominence during the 1500s (known as the “age of
discovery”) as it was an important trade route for the silk trade, and was also used by
sailors to find a route around Africa.
 During the 17th and 18th centuries, European powers sought control of the trade routes in
the Indian Ocean, but Britain was most successful.
 The opening of the Suez Canal in 1869 helped encourage access and trade by Europe to
and through the ocean.
GEOGRAPHY OF THE INDIAN OCEAN
 The Indian Ocean has an average depth of just over 12,000 feet, and has many narrow
continental shelves that average 120 miles in width.
 It is artificially connected to the Mediterranean Sea via the Suez Canal, constructed in
1869.
 The Indian Ocean is located in the Eastern Hemisphere and passes through the Ninety
East Ridge, a structure on the floor of the ocean that runs nearly parallel to the 90th
meridian and is over 3,000 miles long.
 The climates of the Indian Ocean north of the equator, as well as the ocean’s currents, are
mostly controlled by a monsoon climate.
 Due to the melting of polar caps, the Indian Ocean widens by approximately 8 inches
each year.
 The Indian Ocean has limited sea life due to its warm temperatures, as it is difficult for
phytoplankton to grow in most areas, which is a necessary food source for many life
forms in oceans.
 The ocean also has a low oxygen content.
 Although it receives nearly 4,000 miles of river runoff, the water in the ocean evaporates
at a high rate, again due to its temperature.
 Due to its many borders with large countries, the Indian Ocean is considered to be a
“closed ocean”.
 On average, the Indian Ocean maintains a temperature of 71℉ (although this is warmer
nearer to the Equator where temperatures closer to 82℉ are commonly recorded).
 An abundance of seamounts can be found in the Indian Ocean, particularly in the Central
Indian Basin.
 Some marine life you’d encounter in the Indian Ocean include whale sharks, dugongs,
sea turtles, sharks, humpback whales, white-throated rail birds, and other tropical fish and
species, including the rare pink pigeon and echo parakeet.
DIVERSITY IN THE INDIAN OCEAN
 The dodo bird (pictured below, right) once existed on the island of Mauritius but is now
extinct.
 Several endangered turtle species, such as the leatherback and loggerhead Turtles live in
the Indian Ocean.
 The discovery of many underwater thermal vents led to the discovery of vent animals
such as mussels, anemones, and gastropods. These animals live in the darkness and eat
bacteria, and can convert sulfur into energy.
 Many species of sharks live in the Indian Ocean, including whale sharks, hammerheads,
and great whites.
 You can also find nearly 28 species of anemonefish in the Indian Ocean, and they like to
feast on algae and zooplankton.
TRADE AND ECONOMY IN THE INDIAN OCEAN
 The two most well-known waterways in the Indian Ocean are the Suez Canal (pictured
below) in Egypt and the Strait of Malacca between Malaysia and Indonesia.
 Singapore has the busiest container port on the Indian Ocean, and Durban (located in
South Africa) is the largest and busiest port in Africa.
 The Northern Indian Ocean is the most important trade route for oil. It connects the
Middle-East with Asia, and each day tankers carry about 17 million barrels of crude oil
from the Persian Gulf.
 40% of the world’s offshore oil production comes from the Indian Ocean.
Indian Ocean Worksheets