Physical Geography, California Style

By Alan Shrake

An introduction to physical geography, using California as the prime example for all processes and features.  Geographic terminology, the academic vocabulary, is underlined.  Students can find associated media on their electronic devices in order to compare and contrast places in the state and around the world.

• Language: English
• Publisher: Alan Shrake
• Release date: Apr 28, 2019
• ISBN: 9781386415169

Book preview

Ch. 1: Introduction to Geomorphology Module

Various processes have shaped the Earth over the last four billion years, back to the Pre-Cambrian era on the geologic time scale, and are still active today.  The past is the present.  These processes are examined in the following chapters under each subdiscipline.

Plate tectonics provide movement and material to create rocks and mountains subject to erosion, weathering, and mass wasting to form valleys and soils.  Landforms are subjected to seismicity, igneous activity, diastrophism, cave and karst, and coastal formation.

The origins of the Earth, however, actually go back further, therefore we start with the cosmology of our planet.

Ch. 2: Cosmology

Did you know there’s another California in space? 

The California Nebula in the constellation Petreas, northeast of Orion and Taurus.  A nebula is a gaseous cloud gathering more gases and matter, gravity, density, pressure, and heat until finally starting the thermonuclear fusion process (4H-1He) and a protostar is born, releasing radiant energy throughout space. 

Solar energy powers all of Earth’s processes except chemosynthesis, hydrothermal vents, radioactivity, and tides.  Harmful radiation is deflected away from the Earth by the Van Allen Belts.  California has the greatest solar energy potential in the country, but that still accounts for only 10% of power generated in the state.   

All of the celestial bodies in our Solar System, the planets, moons, asteroids, meteors, and comets, were formed through the Nebular Hypothesis described earlier. 

The Earth, Sun, and Milky Way are moving through space toward the constellation Vega, due to the Big Bang about fourteen billion years ago, which shot gas and matter throughout space, that then slowed down (Doppler effect), and coalesced into nebulae.  Therefore, we are never in the same place twice, in three-dimensional coordinates. 

The Moon was part of the Earth until a planetary collision 4.5 billion years ago.  It is only 239,000 mi. away, but the resources seem too scarce to support a lunar base.  Ice fields amidst the maria and regolith aren’t sufficient.  Also, there are health effects living in space, such as bone density loss.  California may lead the aerospace industry, but it could be impossible to viably live on the Moon.  Still, we can watch the phases of the Moon caused by exposure to the Sun, maybe see an eclipse.

We may also never colonize an exoplanet since they are all beyond the nearest star, alpha Centauri, which is 25 trillion mi. away.  Especially a hot Jupiter with three suns!  So, we need to conserve and enhance natural resources and life forms on our unique, precious Earth. 

Of the main sequence stars, our yellow star, the Sun, is like Goldilocks, i.e., not too hot, not too cold.  Blue stars may be larger, hotter, and brighter than yellow and red stars, but they burn out faster.  Half of all stars are binary, with a common stellar center of mass. 

In the Sun’s stellar evolution, it will expand into a red giant in about 5 billion years, pulsing the planets away from it, then become a planetary nebula, supernova, white dwarf, black dwarf, neutron star, pulsar, or finally, a black hole, with matter so dense, one thimble full equals millions of tons and no light can escape.  Scientists did just take the first photograph of a black hole, surrounded by a glowing, orange doughnut of hot gas drawn by its gravity.

Malibu may be a star colony, but not like the Milky Way, a galaxy containing over 100 billion stars, including our Sun in one of its many spiral arms whirling around the galactic nucleus. 

The Milky Way will collide with the Andromeda Galaxy in three to five billion years.  Galactic clusters like our Group of 28 join up to become superclusters, the Universe, and perhaps multiverses, with similar breadth in dimensions and micro-/macro-infinity.

On the Sun, sunspots roil from convective currents caused by latitudinal rotation differential.  Solar flares and prominences rain down in the chromosphere, while solar winds of photon particles and energy stream away from the million-degree corona, to Will Rogers Beach and beyond!

Planets are terrestrial (mostly matter, less gas), or jovian (mostly gas, less matter).  Mercury must run fast, with the greatest temperature extremes.  Venus is the only planet to rotate in retrograde, and the only female one.  Mars has the tallest mountain, Mt. Olympus, at 75,000 ft.  Jupiter’s oceans of hydrogen generate twice the heat the planet receives from the Sun.  Saturn’s rings are guided by shepherd moons while its captured slave moon, Phoebe, moves in retrograde.  Neptune’s volcanic Triton is also in retrograde.  The axis of Uranus is parallel to its plane of orbit.  Pluto, 3.6 billion mi. away, is still a planet, and the coldest, at -382⁰F.  Comets come from the Kuiper Belt (short term) or the Oort Cloud (long term).

And our Earth, close enough to the Sun to support Life, but not too close to burn up or too far away to freeze. 

If you run a magnet through the dirt in a California playground, you will pick up iron filings, micrometeorites. A meteoroid, meteor, and meteorite are all the same object, in different places on their journey.

Lab exercise: Take the students to a dark area on campus to identify planets, stars, and other heavenly bodies, using binoculars or telescope.  Discuss their characteristics and processes that created these features and write in their lab journals.

Lab exercise: Distribute magnets to the students and ask them to find micrometeorites on campus, store them in a glass jar, and return to the class for show and tell.

Ch. 3: Dimensions and Coordinates

The Earth is like a California orange in many ways.

First, it is spheroidal, bulging out in the middle and flatter at the poles, due to rotational gravity pull, 7,926 mi. in diameter and 24,902 mi. in circumference.  

Secondly, it has a rough surface, from Mt. Everest at 29,035 ft. to the Mariana Trench, 36,000 below sea level.  In California, that’s from Mt. Whitney (14,494 ft.) to Death Valley (-282 ft.).

The geographic grid consists of latitudes running from 0⁰ degrees at the equator to 90⁰ degrees N/S at the poles, always equidistant, and longitudes, or meridians, running from 0⁰ degrees at the Prime Meridian to 180⁰ degrees E/W, always converging towards the poles. 

California is an elongated state, with coordinates of 32.5-42⁰N by 114-125⁰W.  The geographic center of the state is Fresno, at 37⁰N by 119⁰W. 

Time zones run roughly along latitudes.  California is in the Pacific Time Zone.

Cartography is the science of depicting the Earth on a map.  Because the Earth is three-dimensional, projections have to be used to approximate relative size and shape of features, azimuthal, conic, elliptical, Mercator, equidistant, and Lambert conic. 

Other mapping applications are Global Positioning Systems (GPS), Geographic Information Systems (GIS), Landsat photography, and photogrammetry.

Considerations in mapping include the great circle, rhumb line, fractional scale, and graphic scale.

Lab exercise: Ask students to use a coordinate list to find places in California and around the world on a globe, map, or computer screen.  Make it a game, rewarding speed in identification. 

Lab exercise: Use USGS topographic quad maps to identify surface topography extremes with topographic profiles and contour lines.

Lab exercise: Distribute GPS devices to the students and ask them to walk the campus recording their coordinates in their lab journals.

Ch. 4: Plate Tectonics

The Earth is also like a California orange in that its lithosphere, or peel, crust on top, is broken up into thirteen large and thirteen small pieces called tectonic plates, that move on top of the viscous, ductile asthenosphere and lower levels of the mantle, or fruit, and the inner/outer core, or seeds, at about 2 in./yr., in a convergent, divergent, or transform manner, determining the geologic evolution of our landscape.  Plate combos are continental-continental, continental-oceanic, and oceanic-oceanic.

California has each tectonic plate movement, joined together by the San Andreas Fault.  The state first grew by convergent plate movement with subduction and accretion onto an original coastline located on the edge of North America in western Nevada. 

The White Inyo Mts. north of Owens Valley date back to the Pre-Cambrian era, 700 million years ago, the oldest rock in California, granitic bedrock overlain with sandstone and dolomitic limestone.  They also contain the oldest bioherm in North America, a reef made from living organisms, in this case sponges and cyanobacteria.

Then came stationary magma plume hotspot activity leading to the Long Valley caldera, associated with geysers and hot springs.  To the north, the Modoc Plateau was later formed by fissure eruptions as the North American Plate rode