IB Geography practice questions.

In a steep upland reach of the River Tees in northern England, turbulent flow forces water and compressed air into joints in the resistant dolerite, and the repeated pressure prises whole blocks out of the bed. Which erosional process is described?

• Abrasion (corrasion) by the bedload
• Attrition between transported particles
• Hydraulic action
• Solution (corrosion) of the bedrock

Answer: Hydraulic action

Hydraulic action is the mechanical force of water and trapped air alone; abrasion needs sediment as a tool, attrition only wears down the load itself, and dolerite, unlike limestone, is effectively insoluble on the timescale of channel erosion, so solution removes a negligible amount here.

During a strong El Nino event the trade winds over the tropical Pacific weaken and warm surface water spreads eastwards towards the coast of Peru. Which change to the coastal ocean off Peru follows most directly?

• The thermocline deepens and nutrient-rich upwelling is suppressed
• The thermocline rises towards the surface and upwelling strengthens
• Offshore Ekman transport intensifies and surface salinity rises
• Cold water sinks along the shelf and phytoplankton multiply

Answer: The thermocline deepens and nutrient-rich upwelling is suppressed

Upwelling only delivers nutrients if the cold, nutrient-rich layer lies close to the surface; with the thermocline pushed down, the weakened trades drive less upwelling and what still rises is warm, nutrient-poor water from the deepened mixed layer.

Northern Chile's Atacama Desert lies directly on the Pacific coast, yet many of its weather stations record no measurable rain in most years. Which combination of controls best explains this extreme aridity?

• Subsiding subtropical air, a cold offshore current and the Andean rain shadow
• Rising equatorial air, a warm offshore current and persistent onshore trade winds
• High altitude, permanent snow cover and a semi-permanent polar high
• Winter monsoon reversal, katabatic winds and a deep coastal fog layer

Answer: Subsiding subtropical air, a cold offshore current and the Andean rain shadow

Air that rises at the ITCZ subsides at about 30 degrees S, warming and drying, while the cold Humboldt Current chills the lowest air so that moisture is lost as coastal fog rather than rain. The Andes block moist air arriving from the east, so all three controls act in the same direction.

Along the Reykjanes Peninsula in Iceland, earthquake foci are almost all shallower than 15 km, fissures open repeatedly and fluid basaltic lava erupts from them. Which plate boundary type is described?

• A conservative boundary, where crust is neither created nor destroyed
• A divergent boundary, where new oceanic crust is formed
• A convergent boundary, where oceanic crust is subducted
• A collision boundary, where two continental plates are crumpled upwards

Answer: A divergent boundary, where new oceanic crust is formed

Fluid, low-silica basalt escaping through fissures together with only shallow foci is the signature of crustal extension; a subduction margin would add a deepening band of foci and viscous, silica-rich magma.

A resident of Lyon, France travels to Marseille and stays four nights with relatives, paying nothing for accommodation. Under the UNWTO definition used in IB Geography, how is this trip classified?

• Domestic tourism
• International tourism
• Same-day recreation, not tourism
• Visiting friends and relatives, which is excluded from tourism statistics

Answer: Domestic tourism

Tourism requires travel away from the usual environment with at least one overnight stay; whether accommodation is paid for is irrelevant and visits to friends and relatives are counted like any other purpose, so a stay that never leaves France is domestic rather than international tourism.

Study Table 1, which shows three food and health indicators for three countries. Which statement is fully supported by the data shown?

• Country Q's energy supply exceeds average needs, yet one child in five is stunted
• Country R has the shortest life expectancy at birth of the three countries shown
• Country P can have no nutrition problems because its energy supply is the highest
• Stunting in Country R is caused by the low dietary energy supply recorded in the table

Answer: Country Q's energy supply exceeds average needs, yet one child in five is stunted

Only the first statement stays inside the table: Country Q's 2 900 kcal is above the 2 200 kcal reference requirement printed below the data, yet 21 % of its under-fives are stunted. HALE is not life expectancy at birth, and three cases cannot establish a cause.