Comprehensive Notes: Unit 1 – Physical Geography of Latin America

Course Logistics and Setup

• First day summary: reviewed syllabus and policies; two main tasks for today:
  • Start unit 1 lecture material (physical geography of the region).
  • Complete seating chart (will occur around 11:10).
• Attendance and participation:
  • Thanking those who are here; effort to fill empty seats; seating chart day emphasized.
• Course structure for Unit 1 (Latin America):
  • Lecture workflow: physical geography first, then human geography on a country-by-country basis.
  • The unit provides a template for the rest of the semester.
• Lecture note-taking slides:
  • Each slide has a location title at the top; these labeled locations appear on maps and are eligible for map questions on exams.
  • I will not ask math questions about places I have not shown in class; online quizzes will mirror this (no math questions about unshown locations).
  • The first online quiz opened yesterday and remains accessible for about four weeks.
  • The slides also highlight key terms at the top; take notes on those terms and answer the slide questions.
  • Use the slides and your notes to study for the first exam.
• Map practice and labeling:
  • You have labeled maps in your slides; you are encouraged to label maps yourself in class (practice, repetition, memorization).
  • Maps are about a quarter of your exams, so get comfortable with locations.
• Practical study tips:
  • If you want to be sure of your seat, write your seat info in your phone (e.g., 1310 Seat Row C, Seat 20-1) so you can find it quickly next class.
  • If I mispronounce a name, correct me during class; it helps with roster accuracy.
• Textual reminders:
  • The course uses a consistent set of maps and projections; no varied projections to prevent confusion.
  • For this region, the two maps are Middle America and South America. The maps shown in class and the blank copies on the course platform (TANS) will be the same ones used on exams.

Unit 1 Overview: Physical Geography then Human Geography

• Latin America is large; unit starts with physical geography (water bodies, landforms, etc.).
• After physical geography, we proceed to human geography using a country-by-country approach within the region.
• Regional scope and scale considerations:
  • Latin America is extremely diverse in both physical and human aspects; the course will use broad regional criteria (e.g., shared language history, major religion, and geography) to structure content while acknowledging diversity.

Four Basic Landform Types (Intro to Classification)

• Mountains
  • Characteristics: high elevation, steep slopes, jagged peaks.
  • Examples introduced: Sierra Madre Oriental (eastern Mexico) and Sierra Madre Occidental (western Mexico).
  • Elevation note: both ranges tend to top out around
    h \approx 13000\ \text{ft}
  • These ranges are part of a broader system (Cordillera) that parallels coastlines.
• Hills
  • Characteristics: smoother slopes, gentler gradients, rounded peaks.
  • Elevation: typically a few thousand feet above sea level.
  • Local example: Texas Hill Country along Ranch Road 12 toward Wimberley.
• Plains (Planes)
  • Definition: a flat but gently rolling surface (the correct term used in class is “plane”).
  • Example: Gulf Coastal Plain along the Texas coast, and the North American Panhandle near the Canadian River area.
  • Elevation: relatively flat with minimal elevation changes over large distances.
• Plateaus (Mesas)
  • Definition: a flat, elevationally raised surface that is higher than surrounding terrain.
  • Example: Central Plateau of Mexico; Central Mesa of the Chihuahuan Desert region.
  • In the ecosystem, plateaus provide distinct land use and climate conditions compared to surrounding plains or mountains.

Latin America Mountain Cordilleras and Elevations

• Sierra Madre system (Mexico)
  • Oriental (east) and Occidental (west) branches.
  • Naming cue: Oriental = East; Occidental = West; helps distinguish the two ranges.
  • Both are continuations of a larger North American mountain system (the Rocky Mountain Cordillera).
  • Elevations in both ranges are generally similar; Oriental tends to be a bit higher on average than Occidental.
• Cordillera concept
  • Definition: a mountain range that parallels a coastline.
  • The term describes how ranges in the Americas fit into broader tectonic processes.
• The Central Plateau and the Central Mesa (Mexico)
  • Central Plateau (also called Central Mesa in places): a large elevated plain between the Sierra Madre ranges.
  • The Chihuahuan Desert is a key desert region located in this area.
• The Gulf Coastal Plain and surrounding lowlands
  • Example: Gulf Coastal Plain, which includes flat, low-lying terrain suitable for certain agricultural uses.

Mexican and Central American Inland Geography: Climate and Land Use

• Chiapas Highlands (Southern Mexico)
  • It is a highland region with peaks higher than those of the Sierra Madre ranges.
  • The state of Chiapas is dominated by the Chiapas Highlands; Mexico is divided into 31 states (Estados Unidos de Mexico).
  • Indigenous population concentrations: southern Mexico (e.g., Chiapas) has large populations of Native American/indigenous descent.
• Socioeconomic and historical context for Chiapas
  • Longstanding marginalization and social issues among indigenous groups, including limited access to education, healthcare, and employment opportunities.
  • 1994 uprising: EZLN (Ejército Zapatista de Liberación Nacional) rose up on 01/01/1994 in response to NAFTA.
  • NAFTA context: NAFTA went into effect on 01/01/1994; it aimed to create a free trade zone among Canada, the United States, and Mexico.
  • Impacts of NAFTA on farmers: about 2,000,000 Mexican farmers were bankrupted by US-subsidized corn imports post-NAFTA; this contributed to discontent and uprisings.
  • The uprising achieved limited goals but highlighted indigenous rights issues and started government responses to improve conditions; however, centuries of marginalization require longer-term improvements.
• Geography and economic development in Chiapas Highlands
  • Rugged mountainous terrain increases costs of infrastructure and development; harder to attract investment in the highlands.
• Central American Mountains (regional scale)
  • Across Guatemala, Honduras, Nicaragua, and other Central American states, there is a belt of mountains often referred to as the Central American Mountains or Highlands.
  • These mountains can reach around
    h \approx 15000 \text{ to } 16000 \ \text{ft} above sea level in some peaks.
  • Orographic effect: these mountains influence weather and climate patterns across the region.

Weather vs Climate; Prevailing Winds and the Orographic Effect

• Weather vs climate definitions
  • Weather: short-term atmospheric conditions (day-to-day).
  • Climate: long-term patterns of weather in a region.
• Prevailing winds
  • In the United States and much of the region, prevailing winds are typically from the west in some regions and easterlies in others, but for Central America, the focus is on easterly trade winds originating from the Caribbean Sea.
  • These winds carry warm, humid air masses toward the mountainous region.
• Orographic effect (or orogenesis/orogeny relevance)
  • When warm, humid air masses move up the windward slopes of mountains, they cool as elevation increases, leading to condensation and higher precipitation on the windward side.
  • Leeward slopes (the side facing away from the prevailing winds) are typically hotter and drier due to descending air and reduced moisture.
  • Central America example: windward Atlantic Caribbean slopes receive more precipitation; Pacific coast (leeward side) is drier and hotter.
• Population distribution related to the orographic effect
  • Because the Atlantic Caribbean coast is wetter and often more challenging for crop farming due to humidity and rainfall distribution, many Central Americans have settled on the Pacific coast, which is generally drier and more conducive to certain types of agriculture and settlement patterns.

Andes and Plate Tectonics: The Modern Geomorphology Paradigm

• The Andes as a major South American feature
  • The longest mountain range on Earth, running along the western edge of South America.
  • The Andes form a defining western spine from north of Venezuela through Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina to the southern tip.
  • It is a classic example of a Cordillera (coastline-parallel mountain system).
• The prevailing theoretical paradigm in geomorphology
  • Continental drift (early 20th century): proposed by Alfred Wegener (pronounced Wagner) in 1912.
  • Wegener's theory: continents once formed a supercontinent and drifted apart; initial reception was highly skeptical.
  • Plate tectonics (modern theory): explains that Earth’s surface is divided into tectonic plates that move over a partially molten mantle.
  • Plate tectonics accounts for earthquakes and volcanism, which are concentrated along plate boundaries.
• Plate tectonics basics
  • Major plates and numerous minor ones move relative to one another; their interactions shape landforms.
  • Plate boundaries are where most earthquakes and volcanic activity occur.
  • Example of subduction: Nazca Plate subducting beneath the South American Plate; this subduction has driven the uplift of the Andes and remains an active process.
• Notable peaks and volcanism in the Andes
  • Mount Aconcagua on the Chile-Argentina border: approximately
    H_{Aconcagua} \approx 22831 \ \text{ft}
  • The Western Hemisphere’s tallest peak; many other 20,000+ ft peaks exist and are still growing due to ongoing tectonic activity.
• Major seismic and volcanic activity correlations
  • The world’s earthquakes and volcanic eruptions tend to align with plate boundaries, reinforcing plate tectonics as the explanatory framework.
• Angel Falls and the Guyana Highlands (Venezuela)
  • Angel Falls, located in the Guyana Highlands of Venezuela, is often considered the highest uninterrupted waterfall on the planet.
  • Height: ≈
    H_{AngelFalls} \approx 3000 \ \text{ft}
  • Definition of uninterrupted: the waterfall maintains continuous flow from top to bottom without a break.
• Mineral wealth of the Guyana Highlands
  • This region is rich in minerals, notably bauxite (ore of aluminum).
  • Bauxite deposits spread across Venezuela, Brazil, Guyana, and Suriname; these are major exporters of bauxite to the United States.
• Aluminum production chain in the Guyana Highlands region
  • Bauxite ore processing sequence:
  • Bauxite → alumina (refining; needs relatively shallow extraction, typically up to ~50 feet depth):
    ext{Bauxite} \rightarrow \text{Alumina}
  • Alumina → aluminum via electrolysis (the Hall–Héroult process):
    \text{Alumina} \xrightarrow{\text{electrolysis}} \text{Aluminum}
  • Economics and recycling
  • The electrolysis step is energy-intensive; recycling aluminum is often more economical than producing new aluminum due to electricity costs.
  • Aluminum can be recycled up to 13 times without significant deterioration in quality before eventual degradation becomes noticeable:
    \text{recycling cycles} \le 13\ \text{times}
• Significance for the region and the United States
  • The Guyana Highlands and adjacent countries are major producers and exporters of bauxite and aluminum-related products, impacting global commodity markets and domestic energy economics.

Key Takeaways and Connections

• The unit uses physical geography to build a framework for understanding subsequent human geography topics in Latin America.
• Four landform types (mountains, hills, plains, plateaus) provide a basic vocabulary for analyzing how terrain shapes climate, agriculture, settlement, and infrastructure.
• Mountain systems are connected through the concept of cordilleras and plate tectonics; the Andes exemplify a long, active mountain belt formed by subduction at a convergent plate boundary (Nazca + South American plates).
• Plate tectonics is the modern explanatory paradigm for geomorphology, superseding the older continental drift idea; plate interactions explain earthquakes, volcanism, uplift, and mountain building.
• Orographic effects explain how mountains influence precipitation patterns and climate, which in turn shape population distribution and economic activity (e.g., Central America settlement patterns favor the Pacific coast due to the wetter Atlantic side).
• Economic and social dimensions intersect geography: indigenous populations in Chiapas and the political economy of NAFTA had profound impacts on rural livelihoods, migration, and regional development.
• The reading and lecture materials emphasize using labeled maps and slide-top locations to prepare for map-based exam questions, highlighting the connection between visual geography and assessment.
• Real-world relevance: understanding climate, elevation, and precipitation thresholds (e.g., $P \ge 30$ inches/year for crop viability) helps explain agricultural practices and land-use decisions in arid vs. humid regions.

Key Terms and Concepts to Review (with Quick References)

• Cordillera: a mountain range that parallels a coastline.
• Orographic effect: the rain-shadow phenomenon caused when air masses rise over mountains, cooling and dropping moisture on windward sides and creating drier leeward sides.
• Prevailing winds: typical regional air-mass flow; in tropics, often easterlies from the Caribbean that influence regional climate.
• Plateau (Mesa): a flat elevated area raised above surrounding terrain.
• Plane vs. Plain: a geological distinction used in class to describe flat, gently rolling terrain.
• Chiapas Highlands: southern Mexican highlands with significant indigenous populations and a history of marginalization.
• EZLN (Ejército Zapatista de Liberación Nacional): Zapatista Army of National Liberation; uprising on 01/01/1994 linked in part to NAFTA.
• NAFTA: North American Free Trade Agreement; came into effect on 01/01/1994; had profound implications for Mexican agriculture and rural communities.
• Bauxite: primary ore for aluminum; mining, refining to alumina, and electrolysis to produce aluminum; recycling economics.
• Aconcagua: highest peak in the Western Hemisphere, approximately H_{Aconcagua} \approx 22831\ \text{ft}.
• Angel Falls: highest uninterrupted waterfall (≈ H_{AngelFalls} \approx 3000\ \text{ft}) in the Guyana Highlands, Venezuela.
• Major plates and boundaries: Nazca Plate subducting beneath the South American Plate; plate boundaries are hotspots for earthquakes and volcanism.
• Key precipitation threshold for agriculture: P \ge 30\text{ inches/year} as a general threshold for growing most crops; drier areas are better suited to grazing with irrigation where possible.
• Important historical context: constant themes of colonial legacy, indigenous rights, resource extraction, and regional development embedded within geographic features.

Quick Connections to Study Strategy

• Use map-labeled slides to focus exam preparation on location-based questions; memorize key locations and their relative positions in Middle America and South America.
• Practice drawing and labeling the Sierra Madre ranges, the Central Plateau/Mesa, Gulf Coastal Plain, and the Andes with approximate elevations and orientation (coastline-parallel cordilleras).
• Relate climate and population patterns to topography (e.g., orographic effects driving population density toward the Pacific coasts in Central America).
• Tie historical events to geography (e.g., NAFTA impact on Chiapas’ rural sector, EZLN uprising as a response to economic and social conditions).
• Recognize and explain the role of plate tectonics in mountain-building and regional hazards (earthquakes, volcanoes) across the Americas.

Notes for Exam Readiness

• You will see the exact maps used in class on exams; be comfortable with those projections and labeled locations.
• No need to memorize every country’s state count, but be able to discuss the Chiapas Highlands and its significance to Mexico’s geography and indigenous populations.
• Be prepared to explain the difference between weather and climate and apply the concept to a Central American setting (e.g., wetter Atlantic side vs drier Pacific side).
• Understand the major processes that form and modify landscapes (plate tectonics, orogeny, uplift, erosion) and how they connect to the features discussed (Andes, Sierra Madres, Angel Falls, etc.).