Geography 390

Geography of California

Fall, 2004

STUDY GUIDES FOR MIDTERM AND MAP QUIZ

STUDY GUIDE, FINAL QUIZ

 

PRACTICE FOR MAP QUIZ

Use a copy of the physical map I passed out on the second day of class. Using Pencil, carefully sketch in the locations of the following features, so that you'll be comfortable with where they are when we talk about them. Check with the locations in your text. Don't turn this in - it's for your own study use. This will be good practice for the map quiz and Midterm on October 25.

Locate the following features:

The Sierra Nevada Mountains
The Coast Range
The Klamath Mountains
The Transverse Ranges
The Peninsular Ranges
The Central Valley - San Joaquin and Sacramento Valleys
Death Valley
Owens Valley
Mount Whitney

Additional Physiographic Regions and features

Modoc Plateau
Cascade Range
Basin and Range, or Great Basin
Mojave Desert
Colorado Desert
Salton Sea trough
Sacramento Delta
Rivers: (p. 178 in Selby)
Sacramento River,
San Joaquin River
Owens River
Russian River
Eel River
Salinas River

Tectonic Features:

Faults:

San Andreas Fault
Rogers Creek Fault
Hayward Fault
Garlock Fault
San Jacinto Fault

Volcanic areas:

Mount Shasta
Mount Lassen
Medicine Lake
Mammoth Lakes
Mono Basin

Climate Regions (p. 122, Selby):

Desert (BWh)
Steppe -- semi-arid (BS)
Mediterranean -- hot summer (Csa)
Mediterranean -- mild summer (Csb)
Mediterranean -- cool summer with fog (Csbn)
Mediterranean highland (Ds)

 

MIDTERM STUDY GUIDE

(USE THIS OUTLINE ALSO TO REVIEW FOR FINAL EXAM)

Topics and concepts on this outline may be included on the Midterm portion of the Exam. This Outline of Topics reflects what I feel is important for you to be familiar with from the first half of the semester.You can also use this Outline of Topics to help you plan and organize the content for your group presentation on October 13 and 18. Material from Chapters 1 through 5 in your text, Rediscovering the Golden State by William Selby, may also be included. Use this outline also to review for the Final Exam, which is 50% comprehensive. Topics on this list will be covered only in very general terms in the final exam.

Concepts and Topics

Introduction -- Why is California so Diverse?

Natural Environment

Shape of state, latitude and longitude, relief

Physiographic Regions -- see map page 11 in text

Be able to describe, compare and contrast each of these regions --
What are the major physical characteristics, in terms of relief, elevation (in general), climate, vegetation types, geomorphic processes

Geologic History

See outline of history on web page 390geology.htm, also Fig. 2.1, p. 35, Selby
How did location of Pacific coast change in past 600 million years?
Influence of plate tectonics on formation of California through time
Passive continental margin from ~600-250 million years ago
Late Paleozoic development of subduction zone offshore, with volcanic island arcs, uplift of mountains east of present day Sierra Nevada
Mesozoic, North American plate moved westward as subduction zone also moved west, to where Sierra Nevada is today --
Mesozoic emplacement of granitic plutons, Sierra batholith, over millions of years
Nevada Orogeny, uplift and building of Klamath Mtns, ancestral Sierra Nevada, Peninsular Ranges
Late Mesozoic-Early Tertiary, North American plate subducts and consumes Farallon Plate; exotic terranes dock against North American plate, building land outward, subduction zone migrates farther west, to where the Coast Ranges are today
Mesozoic -- Franciscan Formation is formed, briefly subducted and then uplifted marine sediments
Beginning around 28 million years ago, after the Farallon Plate was consumed, the Pacific Plate collided with the American plate, and the San Andreas transform fault system was born, near where Los Angeles is today. Coast Ranges uplifted and Transverse Ranges rotated into today's position during this period

Earthquakes and Volcanoes

Earthquakes

San Andreas fault system, right-lateral transform fault
Other major faults, Hayward, Rodgers Creek, Calaveras

Recent major earthquakes:

Northridge, 1994, Richter Magnitude 6.7, on blind fault
Landers, in Mojave Desert, 1992, Mag. 7.6, 85 miles of surface rupture
Loma Prieta, Santa Cruz Mtns., 1989, Mag. 7.1, < 1 mi surface rupture

Probability of major quakes in California in next ~20 years:

Parkfield, Central Calif., 90% probability of a Mag 6
Southern California, on San Andreas, Coachella Valley 40% chance of Mag. 7.5; 85% chance of a Mag 7 somewhere in So.Cal in the next 30 years
Northern California, 28% chance of Mag 7 on Hayward fault, 23% chance of Mag 7 on San Andreas. San Andreas and Hayward combined with Rodgers Creek fault, 62% chance that a Mag 6.7 or greater will occur on one of these three before 2024

Effects of surface type on earthquake hazard -- recall map

Solid bedrock, most stable, least shaking
Unstable bedrock, more unstable, prone to landslides
Alluvium, unconsolidated sediment (may be old), increased shaking hazard
Young mud and fill, fresh unconsolidated sediment, greatest shaking hazard, liquifaction danger

Volcanoes

Major potentially active volcanic centers:
Mt. Shasta, Medicine Lake Highlands, Mt. Lassen, associated with Cascades subduction zone
Mammoth Lakes-Long Valley Caldera, associated with overridden spreading zone
Mt. Shasta most recent eruption, steam and ash, 1786
Mt. Lassen, erupted 1914-1917, lava, ash, pumice, violent
Medicine Lake, 1951, mud, steam, gases
Mammoth Lakes area, 1786 in Mono Lake, lava; earthquake swarms and carbon dioxide gas emissions, late 1980s, 1990s

Climate -- highly diverse

Major controls on California climate

Span of latitudes, Oregon to Mexico, 42 deg. N to nearly 32 deg. N, 1500 miles
General Atmospheric Circulation -- Location on west side of midlatitude continent: Pacific High dominates in summer, Westerly storms in winter
Land-water influences -- cold water upwelling along Pacific Coast, fog, continentality inland
Mountain ranges roughly perpendicular to westerly winds, bring series of wet bands alternating with rain shadows
Elevation, below sea level (Death Valley) to 14,000' peaks (High Sierra)

Mediterranean climate overall, dry summers, wet winters

Great variety of climates within this template

Steppe and Desert climates -- Mojave, Colorado, Modoc Plateau to some extent, southern San Joaquin -- highly variable precipitation, great daily, monthly and annual temperature range

Temperature variation, with latitude and proximity to coast, steep temperature gradient from coast inland
Precipitation variation, with latitude and proximity to coast, mountains, elevation
Tule fogs in Central Valley, winters
Review climate variations by Physiographic Region

Vegetation

Review notes from Native Plant Garden tour, readings from text
Great diversity within California, over 5000 species, 900 genera, many endemic, found nowhere else on earth
e.g. Giant Redwood (world's largest tree by volume) Coast Redwood (world's tallest tree), Bristlecone Pine (oldest living tree), also many other smaller plants, camas, native bunchgrasses, carpenteria, some oak woodlands, chaparral communities, etc.
Reasons for diversity: California as an island, cut off by mountains, deserts, ocean from other lands, isolated, plants evolved in isolation for several million years
Meeting of Southern Flora and Northern Flora when Isthmus of Panama closed and Sierra Nevada uplifted, ca. 6 million years ago
Unique Mediterranean climate, plants adapted to seasonal fires
Plant Communities: Chaparral, grasslands, oak woodlands, mixed evergreen forests, mixed montane coniferous forests, redwood forests, and riparian communities, as we saw on field trip
Also desert plants: Joshua tree, yucca, mesquite, sagebrush, etc.
Alien plants, brought in by Spanish and Euroamericans in past 200 years: eucalyptus, annual grasses, pampas grass, Scotch broom, tumbleweed, water hyacinth (choking waterways in Delta)

Mineral Resources

By Physiographic region

Modoc Plateau -- volcanic rocks, pumice, cinder, also peat from Pleistocene lakebeds
Klamath Mtns. -- sulfide deposits including and copper, zinc west of Redding, also gold, pyrite, lead, silver, iron, etc.
Sierra Nevada -- famous for gold, 107 million oz. mined, mostly before 1900; also copper, zinc, all related to intrusions of Sierra batholith and exotic terranes; also marble, granitic rocks used in building, limestone used for cement
Central Valley -- about 30% of state's mineral production, especially natural gas, petroleum, liquid natural gas. Also sand and gravel, glass sand, clay for fire bricks and whitewash, shale for cat litter, peat & gypsum for soil amendments
Coast Ranges -- mercury from cinnabar, 85% of US production, from Santa Clara, Sonoma, Lake, and Napa counties. Also gravel, sand, some limestone, Santa Cruz, for bricks, building stone, aggregates, minor amounts of gemstones, silver, gold, uranium, etc.
Transverse Ranges: petroleum in anticline off coast of Santa Barbara
Mojave and Colorado Deserts -- many diverse minerals, ranked 2nd in nation for non-fuel minerals, especially asbestos, borates, limestone for cement, diatomite, gypsum, tungsten, rare earths, small amounts of gold, gemstones, mercury, magnesium salt, sodium compounds. About 25% of world's production of rare earths at Mountain Pass mine between Barstow and Las Vegas.

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Last revised: 10/18/04