World Geography Mixed Practice — MCQs with Answers (Set 7)

The 2010 Deepwater Horizon disaster struck in the Gulf of Mexico, illustrating how remote, high-pressure deepwater drilling raises the stakes of any single failure.

Fixed platforms work in shallow water close to shore, while semi-submersible rigs and drillships handle deepwater fields far from any coastline, at far higher cost.

A continental shelf is geologically just a continuation of the adjacent landmass, only submerged, so rock layers that formed on ancient coastlines continue offshore without a break.

Ghawar in Saudi Arabia is the world’s largest onshore field, alone supplying about 6% of global oil output.

Turkey’s control of the Bosphorus and Dardanelles under the Montreux Convention gives it leverage to regulate naval traffic between the Black Sea and the Mediterranean.

The Ever Given ran aground and blocked the Suez Canal for six days in 2021, disrupting an estimated $9.6 billion in trade per day.

The Suez Canal is cut through the Isthmus of Suez, carrying about 10-12% of global trade and nearly a third of global container traffic.

About 25% of the world’s traded goods pass through the Strait of Malacca each year, making it the world’s busiest strait.

A strait is a narrow channel of water connecting two larger bodies of water. An isthmus is a narrow strip of land connecting two larger landmasses.

Warmer water holds less dissolved oxygen to begin with, and warming also strengthens the water-layer stratification that blocks oxygen from mixing down, both pushing existing dead zones to grow.

The Arabian Sea hosts one of the world’s largest natural oxygen minimum zones, distinct from a human-caused dead zone but similarly low in oxygen, and warming waters are intensifying it.

Nutrient runoff from farmland across the US Midwest travels down the Mississippi River, feeding one of the world’s largest seasonal dead zones in the Gulf of Mexico.

Excess nutrients from fertilizer runoff and sewage trigger eutrophication, causing explosive algae growth that eventually strips the water of oxygen as it decomposes.

A dead zone is an area of water with too little oxygen for most marine life, a condition scientists call hypoxia.

The report described the world as entering a state of ‘water bankruptcy’ — framing scarcity as a systemic imbalance between demand/depletion and natural replenishment, not just isolated local shortages.

The Nile, like the Mekong and Indus, crosses multiple countries. Upstream dam-building or diversion can directly reduce water available downstream.

Physical scarcity means a region genuinely lacks enough water to meet demand. Economic scarcity means enough water exists nearby, but poor infrastructure or governance prevents access.

About 2.1 billion people, roughly one in four globally, still lack access to safely managed drinking water.

Freshwater makes up only about 2.5% of all water on Earth, and most of that is locked in glaciers and ice caps.

Sognefjord is Norway’s longest and deepest fjord. Geirangerfjord and Nærøyfjord, both smaller, are also UNESCO-listed for their scenery alongside it.

Where a smaller tributary glacier met a larger trunk glacier, the trunk glacier cut its valley much deeper. This left the tributary valley ‘hanging’ above the fjord, so its stream now falls as a waterfall.

This shallow ridge is called a sill. It often leaves a fjord deeper on its inner side than at its mouth.

Glaciers carve pre-existing river valleys into deep U-shaped troughs. When the ice melts and sea levels rise, seawater floods these troughs, creating a fjord.

A fjord is a long, narrow, deep inlet of the sea with steep rock walls, formed by glacial erosion in mountainous coastal regions.

The 1960 Valdivia earthquake in Chile, magnitude 9.5, remains the largest ever recorded. The Tohoku (Japan, 2011, M9.0), Alaska (1964, M9.2), and Sumatra-Andaman (2004, M9.1) earthquakes were all also major, but smaller.