Exam 1 - Physical Geography

Question 1

Internal & external processes

Answer 1

Internal Processes
• Plate Tectonics
• Move apart (divergent)
– Ridges and rifts
• Collide with each other (convergent)
– Subduction: process of one plate being forced under another plate
• Mountain building, volcanoes, earthquakes, trenches
• Slide past each other (transform)
– Earthquakes
External Processes
• Atmospheric & Oceanic Circulation

Question 2

Major landform features

Answer 2

Three Major Structural Zones
– Eastern Highlands (South America)
– Brazilian Highlands
– Guiana Highlands
– Patagonian Plateau(S. Argentina)
– Central Lowlands (South America)
– The Llanos (Venezuela)
– The Amazon Plain
– The Gran Chaco (Paraguay, N. Argentina)
– The Pampa (Middle Argentina
– Western Alpine System (Mexico, C. Islands, Central America & western S. America)
South America - highest mountains in the Western
Hemisphere, geohazards: earthquakes and volcanoes.
Middle America - Central American Volcanic Axis – Panama to Chiapas, Mexico, and some Caribbean
islands

Question 3

Controls of climate

Answer 3

Temperature
– Latitude – seasonal temperature fluctuations are
greater farther away from the equator
• Consistency between daily and seasonal temperature at equator
• Higher temperatures at edges of tropics
• Polar cold fronts can affect parts of Latin America
– Nortes: Mexico, Caribbean, Central America
– Pamperos: (if strong) Gran Chaco, into SW Amazon Basin)
– Ocean currents & Land-sea configuration
• Warm currents: move from lower to higher latitudes
• Cold currents: move from higher to lower latitudes
– Peru Current creates conditions for Atacama Desert
– El Nino cycles disrupt Peru Current
• Lag Time: water heats and cools faster than land
– Elevation
• Main predictor of climate in Latin America, because most lies between topics
Precipitation
– Continentality
• Not as important in Latin America except in northern Mexico, NW Argentina, southern Bolivia
– Atmospheric Pressure Belts
• Low pressures are associated with rain, high pressures are associated with dry conditions
– Prevailing Winds & Orographic Effects
• Prevailing wind belts include the tropical easterlies, the westerlies, and the polar easterlies
• Orographic: windward side of mountains receive rainfall, and the leeward side is extremely dry

Question 4

Climate regions

Answer 4

• Tropical (A)
– Tropical Wet
– Driest month with at least 2.40 inches
precipitation
– Latitude Range: 10° to 25 ° N/S
– Rainforest biome; sufficient rainfall but poor soil = shifting agriculture; agriculture with chemical amendments
– Tropical Wet/Dry
– More than 2 months have less than 2.40 inches precipitation; winter dry
– Latitude Range: 15 ° to 25 ° N/S
– Savannah biome; grasslands and deciduous scrub
• Arid/Semiarid (B)
– Steppe
– Temperature Range: 24° C (43° F).
– Annual Precipitation: from 4 inches in the driest regions to 20 inches in the moister steppes
– Latitude Range: 35° - 55° N/S
– Agriculture potential good with irrigation
– Desert
– They coincide with the edge of the equatorial subtropical high pressure belt and trade winds.
– Temperature Range: Hot or Cool depending on latitude/elevation
– Annual Precipitation: all months less than 4 inches
– Latitude Range: 20° - 35° N and S
– Agricultural potential if irrigated but can lead to salinization
• Temperate (C)
– Midlatitude
– Humid Subtropical
• Constantly moist; rainfall throughout the year
• Warmest month above 71.6 °F
– Marine West Coast
• Constantly moist; rainfall throughout the year
• Warmest month below 71.6 °F
• West coast of continents from 40 to 55 °N/S
– Subtropical
– Mediterranean
– Dry season in summer
– Warmest month above 71.6 °F
– West/southern coasts between 30 to
40 °N/S
• Cool Humid (D)
• Cold – Highland (H)
• Temperature Range: -18 °C to 10 °C (-2 °F to 50°F)
• Average Annual Precipitation: 23 cm (9 in.)
• Latitude Range: found all over the world

Question 5

Orographic rainfall/rain shadow

Answer 5

• Orographic: windward side of mountains receive rainfall, and the leeward side is extremely dry

Question 6

Altitudinal zonation

Answer 6

• Tierra Caliente – Zero to 3000ft; hot & humid; cold sensitive
tropical crops like sugar cane, bananas, cacao, yams
• Tierra Templada – 3000 to 6000ft; year round mild
temperature; warm weather crops like coffee, flowers,
tomatoes, cucumbers; population centers: San Jose
• Tierra Fria – 6000 to 12,000ft; very cold in upper regions;
mid-latitude crops like maize, wheat, potatoes, broccoli;
major population centers: Mexico City, Bogota, Quito
• Tierra Helada – Above 12,000ft; cold weather crops
possible in lower part (native grains, indigenous root crops)
and animal herding (sheep, llamas, alpaca, vicuna, guinea
pigs); sparse population except in Altiplano (a high
elevation plain in Bolivia)

Question 7

Peru current & El Nino

Answer 7

• Cold currents: move from higher to lower latitudes
– Peru Current creates conditions for Atacama Desert
– El Nino cycles disrupt Peru Current