Ch.1 Introduction To Earth

The Study of Earth Description

Spatial-why is it there, how does it relate to other things.

Geography-from place to place, how things differ and how they are interrelated

-human geography, environmental geography, and physical geography

Global Environmental Change

-Human-caused and natural processes currently altering the landscapes of the world

-special attention to the accelerating impact of human activities on the global environment

Globalization

-processes and consequences of an increasingly interconnected world

-environmental components of the global economy

The Study of Geography

Deductive Reasoning-looking at reasearch

Inductive Reasoning-making a guess

A theory that is absolute is a law

A theory is a best guest which is a conclusion of the the scientific method

International System(SI) vs English System

centimeter, meter, kilometer to ½ inch, 3 feet, 2/3 mile

Enviornmental Spheres and Earth Systems

Lithosphere-is made up of rocks and mineral matter

Atmosphere-is a mix of gasses

Hydrosphere-comprises water in all its forms, frozen water exits in cyrosphere

Biosphere-encompasses all the parts where living organisms exist

Earth systems-a collection of things and processes that operate as a whole

Closed System-self contained system, which are therefore isolated from outside influences and rarely found in nature

Open System-energy can be exchanged across systems as inputs and outputs

ex:glacier systems

Equilibrium-when inputs and outputs are in balance, conditions within system remain the same

Interconnected System-change in one system affects another

Feedback loops

-outputs that feedback into that system, reinforcing change

positive feedback loops versus negative feedback loops

tipping point or threshold

The Solar System

-earth is in the milky way galaxy on the Orion arm

-open system, earth interacts with planets, moons, dwarf planets, comets, asteroids

Origins

-incompletely understoo

-scientific consensus, big bang took place 13.7 billion years ago

-system originated between 4.5 and 5 billion years ago when a nebula contracted into protostar and then into our sun

The Planets

-eight planets revolve in elliptical orbits around

-four inner terrestrial planets are smaller and denser, composed of mineral matter with atmosphere

-four outer jovian planets(gas giants) have deep atmospheres and frozen interiors

The Size and Shape of the Earth

-the earth is 24,900 miles in circumference(40,000 km)

-the moon helps stabilize the earth in its orbit. Without the tilt of the earth there would be no seasons.

-earth is an oblate sphereoid

The Geographic Grid-Lat & Long

Graticule-a grid system of two sets of a line, intersect at a right angle

Plane of the equator-imaginary line through the equator

Equator-earth’s midline

Great Circles-any plane that passes through center of the sphere

Ex:the great circle

Hemisphere-two equal halves of earth

Small Circles-

-do not pass through center

Great Circle Route-path between two points along the arc of a great circle is always the shortest route

Latitude-description of location as an angle north and south of equator

-latitude angles referenced first with N or S

-expressed in degrees, minutes, and seconds, or decimal notation

0 degrees- equator

90 north-north pole

90 south-south pole

Lines of Latitude

Tropic of cancer-23.5 north

Tropic of capricorn-23.5 south

Parallel-is a line that connects all points of the same latitude

-equator parallel at 0 degrees

-other parallels are small circles

Descriptive Zones of Latitude

-bound by seven significant latitudes into bands or zones

-Equatorial, tropical,subtropical, low latitude, midlatitude, high latitude, and polar

-zero degrees latitude - equator

-the earth rotates counter clockwise

Nautical Miles-measured using knots,

Longitude-angular description of location, east or west

-longtitude angles refrenced second with E or W

Meridians-imaginary lines extending from pole to pole

-farthest apart at equator, converge at poles

Establishing the Prime Meridian

-no natural baseline like the equator

-internal conference selected primer meridian

-0 degrees meridian at greenwich,england

Measuring Longitude

-180 degress meridian in the middle of the pacific

-distance between meridians

Earth Rotation on Axis

-rotation from the west takes 24 hours

-speeds varies on latitude

Earth Sun Relations and the Seasons

Circadian-

Dinural-

Rotation Important Effects

-pull of the moon and the sun, effect on tides

-defelection of wind and ocean currents by the Coriolis effect

ellipse-orbit around the sun

tropical year-365.25 days

-earth and sun distance does not cause change in season

Earth is at an inclination of 23.5(axis) and is angled at polaris, the sun.

Polarity of Earth’s Axis-

-axis always points towards the same stars

Perihelion-is the closest point to the sun

Aphelion-farthest point to the sun

declination of the sun-is the latitude receiving vertical rays of the sun

solar altitude-sun’s heigh over the horizon

Circle of Illumination-

June Solstice

-vertical rays strike at the tropic of cancer

-circle of illumination bisects the equator and impacts polar circles

-Antarctic circle dark for 24 hours, artic circle in 24 hours of light

-north pole oriented toward the sun

December Solstice

-north pole oriented away from the sun

-vertical rays at tropic of capricorn

-artic circle in 24 hours of dark, Antarctic circle in 24 hours of light

Two equonix, equal night in day, in spring and fall(march and september)

September & March Equinox

-vertical rays at the equator

-circle of illumination bisects poles, all parallels

-brings 12 hourls of light and dark only that day

Seasonal Transitions

-latitude receiving the vertial rays of sun only between the troics

Day Length

-only equator has constant day lengths

-variation is least in tropics, greatest at high latitudes

-hemisphere patterns are mirror images

Day Length in the Artic and Antartic

-equinoxes and 24 hours of daylight and darkness

Significance of Seasonal Patterns

Tropical latitudes are warm due to high Sun angles and consistent

day length

-Polar latitudes are consistently cold due to low Sun angles

-Midlatitudes have greatest seasonal variation

Telling Time

Standard Time Zone

-24 time zones were created around 24 central meridians spaced 15 degrees apart

-some countries modify or extend across many time zones

Greenwich Mean Time(GMT) or Coordinated Universal Time(UTC)-use prime meridian as reference for standard time

International Date Line

-opposite arc of prime meridian

-runs across teh sparsely populated mid-pacific

-upon crossing, new days begin but time does not change

-line’s displacement due to scattered loctions of some island countries

Daylight-Saving Time

-move clocks ahead by an hour during the summer months

-shifts an hour of daylight to the evening, intially to reduce the consumption of electricity

BC-Before Christ

AD-After Death of Christ

BCE-Before Common Error

ACE-After Common Error