490 likes | 711 Views
Chapter 2. The Physical World Objective : understanding the physical aspects of geography. Why to understand physical features?. A description of a physical place includes the characteristics of the land formation, including types of water in the area.
E N D
Chapter 2 The Physical World Objective: understanding the physical aspects of geography
Why to understand physical features? • A description of a physical place includes the characteristics of the land formation, including types of water in the area. • The terrain of the area (e.g. mountains, hills, valleys, plateaus, etc.), the related vegetation, and the type of surface water affect the potential activities (sports and other outdoor activities – e.g. hiking, boating, fishing etc.) that can be conducted by the travelers. • Land and water may attract the traveler who has varies needs.
Bay Canyon Cape Coast Delta Fjord Glacier Gulf Isthmus Peninsula Plain Plateau Strait Archipelago Cay Dune Foothills Lagoon Reef Major Land and Water Forms
Latitude and Longitude • Where are we? • The latitude and longitude system is used to locate points on the earth’s surface. • The system is expressed in degrees ( ° ). For exact positioning, degrees longitude and latitude are divided into minutes ( ' ) and seconds ( " ) • E.g. Washington D.C. 38° 53' 23" N, 77° 00' 27" W (38 degrees, 53 minutes, and 23 seconds north of the equator and 77 degrees, no minutes and 27 seconds west of the meridian passing through Greenwich, England)
Latitude • Are also called parallels. • Lines of latitude express relative position north or south of the equator (zero degrees latitude). • Zero degrees is the equator, the imaginary line which divides the planet into northern and southern hemispheres. • Latitude is measured from 0° to 90° north or south. 90° north is the North Pole and 90° south is the South Pole. • The climate is usually similar at latitudes that are an equal distance north or south of the equator.
Each degree of latitude is approximately 111km apart. Since the shape of the earth is not a perfect sphere but an oblate ellipsoid, there is variation.
Longitude • Are also called meridians. • Lines of longitude run north and south between North Pole and South Pole. • Zero degrees longitude is established at the Greenwich Observatory, England and is called the “prime meridian” or “Greenwich Meridian”. • Longitude is measured east and west from this prime meridian. The degrees continue 180° east and 180° west (half way around the world) where they meet and form “The International Date Line” in the Pacific Ocean.
The world can be divided into hemispheres in two primary ways – Eastern/Western and Northern/Southern. • The Eastern Hemisphere includes all meridians of East Longitude from 0° to 180°; while the Western Hemisphere includes all meridians of West Longitude. • The Northern/Southern splits the world at the equator with all parallels of North Latitude in the Northern Hemisphere and all parallels of South Latitude in the Southern Hemisphere. • World Latitude and Longitude Outline Map: http://www.enchantedlearning.com/geography/world/latlongoutlinemap/
To locate the coordinates of a point; • Peak a city as an example. • For Latitude: find the equator. Determine if the city is north or south the equator. (N or S) • Always measures north and south. • Determine which two lines of latitude the city is in between. • Determine if the city is closer to the midpoint or one of the lines. • Estimate the degrees Latitude.
For Longitude: Find the prim meridian. Determine if the city is East or West of the Prime Meridian. (E or W) • Always measure east and west. • Determine which two lines of longitude the city is in between. • Determine if the city is closer to the midpoint or one of the lines. • Estimate the degrees Longitude.
Time Zones • World time varies in a direct relationship to longitudinal location of a point. • Earth rotates 15 degrees every hour. (There are 360 degrees of longitude - 180 East and 180 West – on the earth and 24 hours in a day 360 / 24 = 15 degrees per hour). Thus, there is a difference of one hour for each 15 degrees difference in longitude. • In order to have the sun at its highest point in sky at noon everywhere around the world, we need multiple “time zones”.
Determining Time • A plane leaves Munich at 7:00 Sunday to go to New York City. What time will it be in New York City? (flight duration is 8 hours) • Multiple time zones divide the world into 24 15-degree slices and set the clocks accordingly in each zone. • Each zone is one hour different from the next.
Greenwich Mean Time (GMT) • When time is concerned, why is the Greenwich Observatory such a big deal? • World time is measured in terms of relationship to the time at the Greenwich Observatory, England known as the “Prime Meridian”. • Time at the Greenwich Meridian is known as “Greenwich Mean Time” (GMT) or Universal Time. • The Chart, on page 8 of your course book, shows places (countries, cities etc.), number of hours later (+) or earlier (-) than GMT.
What Time Zone Is It? • While traveling (for example, from Munich to New York City), to calculate the time at the arrival point (may be the time in air as well), the number of time zones crossed need to be considered. • Since straight longitudes (time zones) can cut across countries, time differences are usually established along political boundaries. For example, China uses a single time zone and sets its clock to the time in its capital, Beijing. On the other hand, in the US, there are four time zones – Eastern, Central, Mountain and Pacific.
Example 1A • If it is 14:00 in New York City (GMT-5), what time is it in Paris, France (GMT+1)? • time in New York (GMT-5) 14:00 • GMT is 19:00 (14:00 plus 5 hours) • time in Paris (GMT+1) 20:00 (19:00 plus 1 hour) PS: note that the time difference between New York and Paris is 6 hours.
Example 1B • If it is 14:00 on a Monday in New York City (GMT-5), what time is it in Sydney, Australia (GMT+10)? • time in New York (GMT-5) 14:00 on Monday • GMT is 19:00 (14:00 plus 5 hours) • time in Sydney (GMT+10) 05:00 on Tuesday (19:00 plus 10 hours) PS: note that the time difference between New York and Sydney is 15 hours.
Example 1C • If it is 07:00 in Moscow (GMT+3), what time is it in Tokyo, Japan (GMT+9)? • time in Moscow (GMT+3) 07:00 • GMT is 04:00 (07:00 minus 3 hours) • time in Tokyo (GMT+9) 13:00 (04:00 plus 9 hours) PS: note that the time difference between Moscow and Tokyo is 6 hours.
Example 2 • A plane leaves Munich at 7:00 Sunday to go to New York City. What time will it be in New York City? (flight duration is 8 hours) • plane departs at 07:00 in Munich (GMT+1) • GMT is 06:00 (07:00 minus 1 hour) • flight duration 8 hours • flight landing at GMT is 14:00 (06:00 plus 8 hours) • time in New York (GMT-5) 09:00 (14:00 minus 5 hours) PS: note that although the flight duration is 8 hours, departure from Munich was 07:00 and arrival to New York was 09:00.
Example 3A • If a plane leaves Istanbul (GMT+2) at 10:00 and lands in New York (GMT -5) at 15:00 local time, calculate the journey time? • plane arrives at 15:00 in New York (GMT-5) • GMT is 20:00 (15:00 plus 5 hours) • plane departed at 10:00 from Istanbul (GMT+2) • GMT is 08:00 (10:00 minus 2 hours) • the journey time is 20:00 minus 8:00 12 hours PS: (10:00 Istanbul time 22:00 Istanbul time 15:00 New York time) time advantagewhen traveling to west
Example 3B • If a plane leaves Istanbul (GMT+2) at 18:00 on 24th of Feb and lands in Bishkek (GMT +5) at 02:00 on 25th of Feb, calculate the journey time? • plane arrives at 02:00 on 25 Feb in Bishkek (GMT+5) • GMT is 21:00 on 24 Feb (02:00 minus 5 hours) • plane departed at 18:00 on 24 Feb from Istanbul (GMT+2) • GMT is 16:00 on 24 Feb (18:00 minus 2 hours) • the journey time is 21:00 minus 16:00 5 hours PS: (18:00 Istanbul time 23:00 Istanbul time 02:00 on 25 Feb Bishkek time) time lostwhen traveling to east (be careful with IDL)
International Date Line • The International Date Line is the imaginary line on earth that separates two consecutive calendar days. • The International Date Line is located half way around the planet from Greenwich, England. • It is both 12 hours ahead of GMT and 12 hours behind GMT. • It has been recognized as a matter of convenience. Travelers to westward would discover that when they returned home, one day more than they through has passed. This first happened to Magellan.
When the International Date Line is crossed from the east to the west, a calendar day must be added. When the line is crossed from the west to the east, a calendar day must be subtracted. • For example, the Fiji Islands (GMT +12) are west of the International Date Line but the Samoan Islands (GMT -11) are to the east. When it is 15:00 on Tuesday in the Fiji Islands it is still 16:00 on Monday in the Samoan Islands, even though the distance between the groups of islands is no more than 800 miles. Fiji (GMT+12) Samoa (GMT -11) Tuesday Monday IDL
For example, in a trip to the US from Japan on a Monday morning, when the International Date Line is crossed, the day changes to Sunday. On a reverse trip on a Tuesday morning, when the line is crossed, the day changes to Wednesday. http://geography.miningco.com/cs/timetimezones/index_2.htm • The International Date Line is not a straight line. There are zigs and zags in it to avoid spitting apart countries into two days. Lately, in 1995, Kiribati moved a large part of it to the east to be on the same side of the IDL. http://aa.usno.navy.mil/faq/docs/international_date.html
Climate • One of the most important factors which affects where people choose to travel (+proper clothing, likelihood of rain, nature of the terrain, etc.) is climate, especially true for rest and relaxation type vacations. • Climate and weather are different things. • Climate is the average state or condition over a long period of time in an area. It refers to a large geographical region. It is quite predictable. • Weather is the atmospheric condition (e.g. temperature, precipitation, etc) at any given moment in a specific (small) location. It can only be predicted on a short term basis.
Factors affecting climate • There are four primary factors affecting the climate of a location: • Latitude (location north or south of the equator) • Mountains – altitude lowers temperature and prevents weather patterns from crossing • Proximity to major bodies of water • Prevailing wind and ocean current patterns
Latitudinal position • The equator is the line of latitude which splits the world into the Northern and Southern Hemispheres. A destination’s climate changes depending on how far it is from the equator. • Based on the distance from the equator, there are 5 different temperature zones on earth. • Tropical Zone • North & South Temperature Zones • North & South Polar Zones
Tropical Zone: the area between “Tropic of Cancer” (23,5° North Latitude) and the “Tropic of Capricorn” (23,5° South Latitude). There are only minimal changes in warm temperatures throughout the year. • Caribbean islands lie within the tropics. On the other hand, the Bahamas and Florida are located just north of the Tropic of Cancer. Their climate is considered subtropical where winter days are cooler.
North Temperature Zone: the area between the Arctic Circle (66,5° North Latitude) and the Tropic of Cancer. • South Temperature Zone: the area between the Antarctic Circle (66,5° South Latitude) and the Tropic of Capricorn. • Locations within the temperature zones are characterized by changes in temperature through the four seasons. The northern the Tropic of Cancer and the southern the Tropic of Capricorn, the climate is colder.
North Polar Zone: the area between the Arctic Circle and the North Pole. • South Polar Zone: the area between the Antarctic Circle and the South Pole. • Polar Climate is normally below freezing at all times.
The effects of mountains • Altitude has a cooling effect on climate conditions. The higher the location, the cooler the climate. • Lapse rate: for every 305m in elevation you rise, the temperature drops 1,5 degree Celsius. • There is often winter snow near Los Angeles, California, but nothing at the valley below.
Mountains, because of their height, prevent many weather patterns from crossing from the windward (the side of a mountain that the wind hits, generally wetter and greener ) to the leeward (the side of a mountain that is sheltered from the wind, generally drier than the other side) side. Thus on opposite sides of mountain ranges, considerably different levels of precipitation can be found.
Proximity to water • The presence of oceans or other large bodies of water tend to moderate climatic conditions. • The heating and cooling of the oceans are major influences on climate and weather. • Water generally warms and cools more slowly than land. Ocean temperatures drop more slowly with the approach of winter and warm more slowly with the approach of summer than landmasses. For example, it is usually warmer near the shore on a winter day than farther inland. Coastal areas generally have more moderate climates than interior areas at similar latitudes.
Wind and ocean current patterns • The temperature of ocean water changes by location and by the location of major water current. • There are two important facts about water currents which influence the water temperature; • In the Northern Hemisphere, water currents move in a clockwise direction, in the Southern Hemisphere, they move in an opposite direction. • While the currents move westward along the equator, they get warmer, come together at the equator, then when hit a landmass they depart from each other.
E.g. Water is much colder in Los Angeles than southern shores of Japan. The Caribbean Sea and the eastern coast of the US has warmer water than Europe’s Atlantic beaches (at the same latitude). • There are five major water currents; • Gulf Stream (warm) • Japan Current (warm) • Humboldt (cold) • California (cold) • Benguela (cold) • Winds (weather patterns) also flow in currents (see page 5 of your course book).
On the north and south of the tropics in the Northern and Southern Hemispheres respectively, the wind currents move from west to east (colder) “jet stream” E.g. from Istanbul to Ankara. (West is colder, e.g. Iceland is warmer in winter than locations in Greenland and Canada on the same line of latitude). However, in the tropics, they generally move from east to west (warmer) “trade winds”. • Knowing which way the wind blows is important in determining the flying time. E.g. Flying from San Francisco to Tokyo is longer than the other way round.
Seasons • The relative positions of the sun and the earth throughout the year determine the seasons. • The earth rotates around an imaginary line passing through the poles, called the axis. This line forms an angle (called the tilt) of 23,5° with the perpendicular to the orbit of the Earth around the Sun. • Seasons are opposite in the Northern and Southern Hemispheres.
http://www.scienceu.com/observatory/articles/seasons/seasons.htmlhttp://www.scienceu.com/observatory/articles/seasons/seasons.html
The seasons are then the result of this tilt of the Earth's axis. There are differences in how the rays (sun light) from the sun hit the earth throughout the year. When the rays coming from the sun is relatively direct, the weather gets warmer and the days are longer. • Twice each year, approximately March 21 and September 21, the sun is directly overhead at noon on the equator. On these equinox dates, virtually all points on the earth receive twelve hours of sunlight. • Twice each year, approximately June 21 and December 21, the difference between night and day is maximum. On these dates at noon, the sun is at its most northerly or southerly position.
Climates of the World • To identify climates according to temperature and precipitation values, various attempts have been made. Koppen Classification System is the most accepted one. • The Koppen Classification System has five basic climatic types.
A - Tropical humid (tropical rain forest climates); monthly temperature is above 18°C throughout the year. There is no real winter. Rainfall is high, precipitation exceeds evaporation which produces lush vegetation. • B - Dry Climates (includes Desert Climate) • C - Mild mid-latitude (includes Mediterranean Climate); which have pronounced changes of seasons. The temperature in the coldest month is between 18°C and 0°C. • D - Severe mid-latitude (Snow Climates); which have average temperatures during the coldest month below 0°C and during the warmest month average 10°C.
E - Polar (Ice Climates); which have no true summer. Average temperatures during the warmest month is below 10°C. http://www.eduplace.com/ss/maps/pdf/world_clim.pdf http://geography.about.com/library/weekly/aa011700a.htm http://mediterraneangardensociety.org/climate/map.cfm http://biology.about.com/library/weekly/aa012303a.htm http://www.panda.org/news_facts/education/virtual_wildlife/wild_places/tropical_forests.cfm http://www.enchantedlearning.com/biomes/label/desert/labelanswers.shtml
Some Important Terms Referring climate and weather; • Cyclone • Monsoons Referring to measurement of area, distance and temperature; • Centigrade/Fahrenheit • Hectare/Acre • Kilometer/Mile • Lapse Rate
Centigrade/Fahrenheit • Celsius to Fahrenheit × 2 + 32 • Fahrenheit to Celsius - 32 / 2 http://www.cnn.com/weather
Hectare/Acre • Hectares to Acre × 2,47 • Acre to Hectares × 0,4
Kilometer/Mile • Kilometers to Miles × 0,6 • Miles to Kilometers × 1,6 http://goeurope.about.com/cs/maps/l/bl_euro_dist.htm