Earth Science 7 - Los Angeles, California

Geographical Location

Los Angeles, California, USA is a 469 square mile city located at 34°03'N and 118°15'W.

Los Angeles is located at an elevation of 110 meters, 361' above sea level. The city is surrounded by the Santa Monica Mountains to the north and the San Gabriel Mountains to the east.

The body of water closest to Los Angeles is the Pacific Ocean, a major climatic influence. The air over the Pacific Ocean keeps temperatures fairly mild throughout the year.

Climate

Los Angeles is classified as Csa or Csb (dry-summer subtropical or Mediterranean climate) on the Koppen Climate Chart. Mediterranean or dry-summer subtropical climates normally occur between the 30° and 45° latitudes on the western sides of continents.

In the winter, Los Angeles is in the polar front region. The majority of the year's precipitation occurs in the winter. Los Angeles primarily has subtropical high pressure systems, so it is dry, yet hot, in the summer. Near the coastlines, summers may be milder due to cold ocean currents that bring fog and prevent rain. Los Angeles annually averages 329 days of sunlight. It generally has moderate temperature and precipitation patterns. Since Los Angeles has many canyons and valleys, it often experiences mountain and valley breezes.

Common problems are air pollution and smog. Air pollutants often gather near the coasts during times of little air movement. Another important climatic factor is the Santa Ana winds, which bring hot and dusty gusts of up to 50 miles per hour from the surrounding mountains. The occasional flash floods in the canyons cause mudslides. Los Angeles also experiences prevailing westerlies.

Los Angeles has a climate similar to that of Athens, Greece Science 7 - Athens, Greece

View Los Angeles monthly temperatures, humidity percentages, and numbers of hours of daylight at <www.climate-charts.com>.

Weather Averages and Records

Temperature

• The average temperature in is 64°F
• The average high is 74°F
• The average low is 53°
• The average winter temperature is 57°F
• The average summer temperature is 72°F
• The record high was 94°F in 1900
• The record low was 39°F in 1881

Humidity

• The average relative humidity is 39%
• The maximum relative humidity is 89%
• The minimum relative humidity is 13%
• The average dew point is 31°F

Precipitation

• The average monthly precipitation is 0.03 inches
• The record monthly precipitation was 1.55 inches in 1954
• The average annual precipitation is 17 inches

Wind

• The average wind speed is 2 mph
• The average maximum wind speed is 12 mph

Other

• The average visibility is 7.3 miles
• The average sea level pressure is 30.13 inches

Geology

Plate Tectonics

Los Angeles lies on top of the Pacific Plate and is located about 30 miles away west of the San Andreas fault, an active transform boundary between the North American Plate and the Pacific Plate. The Pacific Plate carries Los Angeles northward at a speed of approximately 2 centimeters per year as it moves in relation to the North American Plate.

Underlying Rocks

Multicolored igneous granites and sedimentary sandstone rocks in the colors beige, red, white, and yellow underlie Los Angeles. Many of the rocks are wind and water rounded. One can find rocks containing iron oxides, iron sulfides, and copper near the outskirts of Los Angeles.Los Angeles is located over a deep sedimentary basin with hills that are made up of layered Miocene and Pliocene sedimentary rocks.Miocene rocks are organic sedimentary rocks that are present due to the compaction and cementation of material from grasses and grazing mammals in the Tertiary period. Pliocene sedimentary rocks were formed by the sedimentary deposits of the last epoch of the Tertiary Period.

Map

References

1. National Oceanographic and Atmospheric Administration
2. Weather Underground
3. Library of Congress Country Studies
4. CIA World Factbook
5. World Climate Charts
6. Los Angeles Examiner
7. Water Encyclopedia
8. Geology of Los Angeles, California
9. American Heritage Dictionary

Links

1. Main Page
2. Earth Science 7- Cities
3. Science 7 - Athens, Greece