PENT geography - no pictures

Intro. To Physical Geography

•Geography = Earth + write (measure)

•Where,?  Why ? 

•Location, scenery, shape of land

Rapa Nui

•People arrived by island-hoping probably from the west

•A tropical island full of trees, lots of rain

•People thrived for ~ 1,000 years

•Civilization flourished, even built ~ 900 moais: monuments to the male elders who died

•After most trees were cut, the nutrients of the soil were removed by wind & rain

•Lack of food, environmental disaster

•Still no one knows why the soil is not productive anymore

•Can’t see many nutrients in the soil

•War eliminated most people

•The same is happening on the whole planet today – education is needed

In Canada

•Lack of education? - geography not much in schools

•No respect for environment?

•Canada the only nation to abandon the Kyoto Protocol !

•The Ministry for Environment has been under attack from previous Government

You can become geographers!

•By teaching it at school

•Not much background is needed

•Globes, atlases are found in most schools

•Use basic info from this course

Earth spins on its axis at 23.5 degrees

•The sun appears to rise in the east and move west

•But the sun is stationary

•Therefore, the earth spins eastwards

•Welcome to our planet!

Shape of Earth

•Can be seen during a Lunar eclipse

Location Coordinates

•Latitude: how far from the equator

•Use Parallels (parallel to the equator)

•Use angles (similar to hours)

•Longitude: how far from the prime meridian (zero longitude, through Greenwich, London, England)

•Use Meridians (noon lines)

Shape, size of the Earth

•Lunar eclipse: the moon disappears

•Shape of the earth revealed

•Size of the earth: Eratosthenes experiment

•He observed that the sun is directly above on the longest day of the year at Aswan

•Angle of shadow at noon will give you the size of the Earth!

Great circles

•Straight line on the globe, but curve line on projections

•Shortest distance between any two places on the globe

•Paths of jets lie along great circles

•Latitude: use angle to Polaris star

•Longitude: use the time (clock)

International Date Line

•Starting point for each new day

•Change the date, not the hour

•Cross from east to west: advance 1 day

•Cross from west to east: lose 1 day

Noon

•Highest position of the sun in the sky

•Sundial : time according to position of the sun in the sky

Meridians and Time Zones

•a.m. & p.m.  (ante & post meridium, Latin)

•360 degrees is equal to 1 day or 24 hours

•Therefore, 1 hour is equal to 15 degrees of longitude

•24 time zones (24 X 15 = 360)

Scales

•Example: Manitoba map has a scale of 1 : 1,000,000

•1 cm on the map is equal to 10 km on the ground

•Same units on either side of scale

•World map is 1 : 35 million

•Map of classroom would be ~ 1 : 100

Projections

•Globe in 3D

•Maps in 2D, not as accurate, need to be stretched, esp. away from equator

•Projections on paper have improved tremendously over the years

Remote sensing : satellites

•Need 4 satellites for GPS

Elevations

•Meters above mean sea level

•What is your elevation?

•Highest point in Manitoba is 832 m

•Tallest mountain in N. America is Mt. Logan in the Yukon at about 6 km

•The “roof of the world” is just under       9 km or 8850 m on the Himalayas

•The mean depth of the oceans is about 3.5 to 4 km

•The deepest trench under the sea extends to more than 11 km. Trenches form by subduction of the ocean floor under another part of the crust

To find height of a building

•Courtesy of Thales of Miletus, 480 BC

•First scientist in the world!

•Wait until your shadow is equal to your height

•Then measure the length of the shadow of the building

•It will be equal to its height!

SOLAR SYSTEM

•Only “constant” in nature: speed of light

•300,000 km /sec (is it true?)

•Light reaches the moon in 1.28 sec

•Everything else is relative to it

•Matter & energy are forms of the same thing

•One can be converted into the other (was basis of atomic bomb before it was tested)

Milky Way Galaxy

•Andromeda galaxy: only galaxy visible to naked eye; because it is approaching

•Plan & section of galaxy

•Orion’s Arm

•Voyageur I & II (left in early 1970’s) are about 13 billion km away now

•1 light year is ~ 10 trillion km

The Sun

•Stars grow hotter as they age

•Sun losing matter in the form of the solar wind, but it is losing much more in the form of EM radiation (we call it light and heat)

Distance to the sun

•Elliptical orbit of earth & other planets

•Furthest from the sun: July 4

•Closest to the sun: Jan. 3

•This change in distance makes no difference on our temperature

Sun Spots

•Like storms on the sun, emit plasma into space

•11-year cycle, last one in 2004

•Experiment on moon to test solar wind

•Electrons & protons hit surface because there is no magnetic field

Aurora

•Solar wind hits molecules of gases (N2 & O2) & “ignites” them into colors

•Solar wind blocked by magnetic field

•Only passes into air at magnetic poles

Video : Northern Lights

•We see the charged particles of air

•Best viewing in polar regions

•Effects: weather, health, power transmission (Quebec, 1989:blackout)

•People affected: Alaska, Inuit, Russia, Norway, Lapps

Earth’s Magnetic field

•North Magnetic Pole

•First noticed in 1831 within Arctic islands (NWT, Nunavut)

•Used to be almost stationary for ~ 100 years

•Has moved north since & is speeding up towards Russia

Blue Sky ? Blue Ocean ?

•Space is black (see that on the moon)

•Sunlight illuminates particles of air. These scatter shortwaves, like blue, very effectively. So, sky looks blue

•Does the ocean reflect the blue sky and looks blue or the sky reflects the blue water and looks blue ?

Red, yellow, orange

•Sunset, sunrise: sun’s rays must travel further to get to our eyes. Gases in the air scatter the shorter wavelengths (blues, greens, purples) in all directions, so only longer wavelengths reach our eyes

•The dirtier the air the more colorful the sunsets because dust scatters even more blue light away

•Most dazzling sunsets after forest fires, volcanic eruptions

EM RADIATION

•The shorter the wavelength, the more powerful the energy

•All objects radiate energy in wavelengths related to their surface temperature

•The sun emits UV, visible, IR

•We (warm bodies) emit IR radiation

Sun’s energy

•Incoming radiation is shorter wavelengths (more power)

•Outgoing radiation from the earth is longer wavelengths (less power)

Insolation

•Intercepted solar radiation: heat & light

•Angle of incidence: very important

•Subsolar point

•Paradox: winter in South Pole has max. insolation (24 hours daylight)

•Min. insolation over Sahara desert: no clouds

Reason for Seasons

•Variation of sun’s altitude above horizon

•Revolution: 1 year around the sun

•Rotation: on its axis (no tilt, no seasons)

•Circle of illumination

•Sun’s declination: latitude of the subsolar point. Tropics are the limits

•4 extreme positions

•2 equinoxes (“equal night”) 12 hour-days & 12 hour nights: March 21, Sept.21

•2 solstices (“sun stops”): June 21(longest day), Dec.21 (shortest say)

•Dawn & twilight -diffuse sunlight- (only 30 min at the equator)

Speed of Rotation

•About 1,000 km / hour at 50 degrees N

•1,675 km/h at the equator

•Day length: no light or continuous sunlight beyond Arctic & Antarctic circles

Our Atmosphere

•Ocean of air

•Oxygen in the air: “cleans the air”, very reactive, combines with pollutants to form oxides

•Air: biological product, composition influenced by the living

•Air motion creates currents in the ocean (not vice versa)

•means “steam-sphere”

•78% Nitrogen, 20 % Oxygen

•Ozone layer absorbs UV rays

•Air pressure= weight of air

•Air: “product of the living”

•Air is heated from below (while water is heated from above)

Sections of the atmosphere

•Troposphere: most of air (clouds)

•Stratosphere: no clouds, ozone layer

•Ionosphere: charged ions of gases (aurora)

•Average temperature on surface 15 ‘C

•Temp. decreases upwards at ~ 6 ‘C per km

Natural sources of air pollution:

•Volcanoes, forest fires, decaying plants

•CO: incomplete combustion

•Photochemical reactions: exhaust + UV

•Smog: smoke + fog with sulfur gases

•Acid rain: S,C,N, gases

Energy Balances

•High insolation over desert areas (cloudless)  about 30 ‘ N & 30 ‘ S

•Earth’s reflectivity (albedo): 31 %

•Moon’s = 7 %

•Earth appears 4 X more reflective than the moon (which is rather dark)

Albedos

•Snow : ~ 85 % , reflects

•Black surfaces : 10 %, absorb

•Green surfaces with plants: 25 % absorb - the sun is their food (-6C-40C)

•Albedo of soil with grass:18-25 %

•Albedo of soil without grass: 12-20 %

--> extra heat helps germination!

The Rainbow

•Combination of reflection and refraction (bending) of light by the droplets of water in the air

•Conditions to be able to see it:

•1. The sun is behind the observer

•2. the rain in front

•3. rainbow is 22 degrees up from the horizon

•If you are in an airplane it is possible to see rainbow as a complete circle

Temperature

•Thermometer (used to be mercury)

•Heat: energy flows from higher temp. to lower- when in contact

•Temperature: average kinetic energy of molecules of matter

•Air heated from below (while water heated from above)

Urban heat islands

•Cities warmer than surroundings

•Most surfaces are dark, absorb heat

•Need to make them reflective, such as white

•Windows trap heat, new office windows are shaded, more reflective

Continental / maritime locations

•Water absorbs heat, land does not

•Land has temp. extremes : too far from ocean to be moderated by water

•Temperature Range (difference between highest and lowest)

•Temperature profiles- the bigger the land, the colder it will get

Temperature in the weather

•Wind chill (speed of wind) - winter

•Heat index (humidity) - summer

Atmospheric circulation

•Wind: transfer of both energy & mass

•Air pressure:motion, mass & number of molecules of gases

•Torricelli

•Difference in P produces wind

•Flow from H (dense) to L (less dense)

•Forces: Gravity, Coriolis, Friction

Coriolis Force

•Anything moving deflects due to rotation (speed of rotation varies with latitude)

•To the right (N) or left (S)

•Zero at equator

•The faster the wind, the greater the deflection

Atmospheric circulation

•H created when cold, dense air sinks

•Equator: warm air rises-->creates a L

•Two H and two L

•Doldrums near equator

•Horse latitudes at 30 ‘ (Sargasso Sea)

•Polar are frigid, dry deserts

Movement of air

•Air rises anti-clockwise (turns left)

•Air sinks clockwise (turns right)

•Only for the northern hemisphere

•Opposite in the southern hemisphere

Toilet, sink

•Water goes down anti-clockwise and at the same time air rises

(because in their construction there is a trap under the toilet / sink)

Again, this is for northern hemisphere

In or near the Equator

•Water drains straight down without turning

•Tested by a friend in the country of Equador

Storms, hurricanes

•Turn left (anti-clockwise) in the northern hemisphere

•Turn right in the southern hemisphere

•Because the air that rises turns into clouds

Jet streams

•300 km / h

•200-500 km wide, 1-2 km thick

•Move eastwards at about 11 km up

•When there is storm, the jet stream is right above it

•Used by Japanese during WWII

•Used by balloonists – see video

1^st Video: Jet Stream

•Paper balloons sent by Japan during WWII to bomb North America

•They knew about the Jet Stream (first people to do so)

•Balloons need to heat the air (inside) in order to rise

•Speed of wind

•No wind means no waves in the ocean

2^nd video: The Stardust Mystery – 1947

•Plane disappeared only to re-appear 53 years later at the bottom of a glacier

•Two mysteries:

•1. Why it disappeared?

•2. Why wreckage was 50 miles off course

•Crash took place on top part of glacier

•Glacier is a river of ice, it moves downhill slowly

•Glacier swallowed plane and moved it downhill UNDER the surface

•Plane flew straight into the Jet Stream and slowed it down

•They thought they had crossed the Andes when they started the descent

Local winds

•Land -sea breezes

•Mountain (katabatic) breezes

•Monsoonal (=seasonal)

•World record rainfalls

Ocean currents

•Frictional drag of the winds on water surface

•Other factors: density(due to temp,salinity)

•Equatorial currents-->piling east shores

•Starts at the poles, water freezes (salt taken away), so water beneath is salt-rich, more dense, colder, sinks,flows towards equator, flow is anti-clockwise

•So, western shores of continents are warmer than eastern shores

Deep ocean currents

•Long conveyor dives in north Atlantic & surfaces in

• when water swept away from shore, new cool ,nutrient -rich upwells (prime fishing)

•Cycle takes 1000 years

Next topic is WATER

•Gives the POWER to the weather system

•Decides how powerful the wind, the storm, the hurricane, the tornado will be

Water & Moisture

•Powerful interaction of moisture & energy

•Moisture in air: very dynamic

•Water in the air: 50 % by evaporation, 50 % by oxidation of methane

•Evaporation to precipitation takes ~ 11 days

•Not compressible, otherwise the bottom of ocean would turn into solid (ice) !

•Used in hydraulics, like the car breaks

•Has 1 oxygen, two hydrogen atoms

•Water is like a Universal solvent

•Ice is less dense (heavy) than water : this is abnormal, another abnormality:

•Ice expands to form 6-sided structures

•Ocean has average depth of 3.73 km

•(Mars: lost its water through low pressure)

•Milk is 83% water

•Snow is WHITE, because of the air trapped between crystals. If compressed into ice, it loses the white color

•Covalent bond, very strong

•H bonding (without it, it would be gas at normal temp.)

•Sticks to things: surface tension, capillary action on glass (it ‘climbs’ the wall)

•Change of state needs energy

•Latent heat energy: to overcome H bonding

Water : 3 natural states

Ice to water needs 80 cal (for 1 gram)

•Water to steam needs 540 cal (1 gram)

•Clouds release staggering amounts of heat

•Latent heat : hidden, can’t be detected with thermometer

Latent heat observations

•When snow falls, it is “warm”

•When snow melts, it is “cold”

•Clouds are powerful, the bigger the more powerful (pilots avoid them)

•Clouds are “warm”

•Fog (cloud on the ground) is “warm”

Humidity= water vapor in the air

•Depends on the temperature :

•Warm air = like a large sponge

•Cool air = like a small sponge

•Dew point temp: Temp. at which air becomes saturated (with water vapor)

•Cold drink ‘sweating’: where is the water coming from?

•Cold surface cools the air around it, & makes water vapor in the air condense, or turn into liquid

Humidity variation during the day

•At sunrise : max., can be 100 % when you get water on the ground, the car

•As the temperature rises, the humidity drops : min. in the afternoon

Humidity: adiabatics

•Hair Hygrometer: hair changes as much as 4%, gets longer when wet

•(Adiabatic processes: no external influence)

•Low density air rises, less P, expands, cools, becomes less dense & forms clouds

•High density air sinks, higher P, compressed, warms, denser

Temperature drops as the air rises

•Dry adiabatic rate (DAR) = 10 degrees C per km – below the cloud

   Moist adiabatic rate (MAR) = 6 degrees C per km – inside the cloud

Clouds

•Unstable air, warmer than surroundings, rises, expands, cools, condenses, forming clouds

•Condensation needs nuclei: aerosols, dust

•Stage 1: condensation forms water droplets

•Stage 2: A million droplets make 1 raindrop

•Fog : cloud in contact with ground

•The darker the cloud the more water it contains (because it blocks the sunlight)

•Dark clouds have tremendous amount of water & latent heat energy

•They are capable of doing lots of damage

Types of clouds

•Stratiform: “stratus”

•Puffy : “cumulous”

•Wispy : “cirrus”

•Above 6 km : just ice crystals

Fog

•Air temp. = dew point temp.

•Fog is warm

•Usually capped by an inversion layer

•Advection fog: sea smoke, valley fog, upslope fog

•Radiation fog : over moist ground at night

•Can be harvested, in deserts like Atacama

Can you modify the weather?

•Soviets had always the May1st parade under sunny skies

•They were able to change the weather

•During the Cold War (1960’s to 1980’s) a combined USA / NATO military exercise in the Arctic was blocked by sudden snowstorm!!! – prob. The Soviets created it

•Now the Chinese have a Ministry of Weather with 3,000 scientists & ½ million casual workers

•Making rain & snow is not difficult

•Neutralizing a storm / tornado/ hurricane, etc is a bigger task, but can be arranged

Weather

•System of chaos!! (Suzuki)

•In Canada, unpredictable

•Around the Equator very predictable: always the same – clear in the a.m., rain in the p.m.

•In the desert areas, very predictable

•The problem is in the mid-latitudes

mid – latitudes

•40 – 60 degrees North & South

•Most people in the northern hemisphere

•Precipitation only by air mass collision: warm air from the south collides with local –normally cool air

•“Warm front” or “ cold front”

Barometer

•Gives you the warning

•Also, the high - level clouds

•In this way, it is a bit predictable

Air mass collision

•“Air mass”: the local air

•Dry over continents / Moist over the oceans

•Air in motion due to unequal heating of the planet – it Has to move

•In N. America: warm air from Gulf of Mexico / Pacific Ocean is flowing to the north bringing rain/ snow with it

•The results of the collision depends on the nature of the air masses, the greater the contrast in temp., pressure, humidity, etc the more violent the weather

•High cirrus clouds 6 hours or more before collision is the warning

•Cold Front

•40 km /hour +

•The cold air is moving

•Quick, heavy rain

•May also have lighting, hail, tornado

•Temp. /humidity drops

•Warm Front

•20 km /hour +

•The warm air is moving

•Slow, light rain

•Temp. /humidity rises

•Cold front and warm front along same boundary

•Collision ends when the faster-moving cold front overtakes warm front

•Clear skies after collision ends

•Next collision may come soon after or long time after

•They move from west to east and can go around the globe

Greenhouse Effect

•In a greenhouse the incoming solar radiation can go through glass or plastic, but it cannot exit once inside

•That is because it loses its power and is unable to go through the glass

•Therefore, the energy is trapped inside the greenhouse and its temperature rises

The Earth is like a greenhouse

•The energy that bounces off the surface is absorbed by the so-called greenhouse gases

•Most prominent is CO2. It is emitted by volcanoes

•Since the Industrial Revolution it is also emitted by all engines that burn fossil fuels like gasoline, diesel & all oils

•The amount of CO2 emitted by human activities increases dangerously and has increased global temperatures

•Consequently, the weather is getting very extreme as a result

•It is time to reduce the emissions of CO2 or face the consequences

•Methane is also a greenhouse gas

Video on the Greenhouse Effect (1990)

•Weather predictions do not look good if humans continue to burn fossil fuels

•It is necessary to limit emissions so that future generations don’t suffer the extreme weather phenomena associated with Global Warming

Weather & Health

•Narrow temp. range that is comfortable

•If cold, stress to the heart & less resistance to infections

•If dry, skin problems

•If hot, bacteria thrive & bring diseases

•Sudden changes (cold front) are hard for the aged

•Windy days: children misbehave, head aches increase & mental health affected

•Heat waves lead to violence (must be ancestral when we were cold-blooded like the snakes)

•Lack of sunshine lead to depression

lightning

•Benjamin Franklin proved (with a kite & a key hanging on it) it was electricity, not fire (speed of light)

•30,000 degrees C

•Heated air expands violently, we call it thunder

•Thunder travels much slower than light

•Electricity prepares a path to travel from cloud to ground

•Get your warning and act fast!

•Avoid telephone, water, shower, metal surfaces & away from windows

•Outside avoid under tree or golf greens

•Canada: 6 deaths, 125 injured / year

•USA: 200 deaths

•Can cause a blackout

•New York, 1977: took 25 hours to fix it

•Florida: lightning capital of N. America

•Most common: along the Equator

•2010 brought down Air France plane coming from Brazil

Freezing Rain or Sleet

•Rain falls through a narrow layer of cold air near the ground

•However, freezing is a slow process, because of the large release of latent heat from so many water drops & the air has ample time to escape (that is why ice is so clear)

•Water “supercools” extremely fast into glazed frost, it freezes on impact

Hail

•Ice crystals fall from top of cloud & pass through super-cooled water droplets which freeze immediately

•Vigorous up and down currents in a cumulonimbus cloud may make hail bigger

What comes down

•1843: alligator in S. Carolina

•1857: live lizards in Montreal

•1859: fish covered the ground, Wales

•1876: fresh meat (mutton?) in large snowflakes

•1877: snakes, Memphis, TN

•1895: huge black African ants Winnipeg

•1903: fish, Moose Jaw, Sask.

•1921: frogs in Calgary

•1951: ducks inside hail, Maine

•1977: fresh, ripe hazelnuts, UK (local ones don’t ripe until 6 months later)

•1979: frogs on a Greek village

•1983: sea shells, UK

•In Ethiopia, many times fish dropped from the sky during the famine

Tornado (twister, funnel cloud)

•Mostly along the “Tornado Alley” where they get 1,000 / year from April to June

•Now have spread to Canada & elsewhere – people “surprised  ” in many other countries

•Spinning of air from air mass collision

•High humidity noticed during tornado events

•Can be predicted from satellite data or a doppler radar dish on the ground (it picks the rotation in the cloud)

•A house would explode from the tornado’s extreme low pressure

•A dust devil is not a tornado

•A “tornado fire” in Winkler, 2000 killed 1 person: someone put a match on stacks of hay

Elie tornado, 2007

•Most powerful in Canada, category F5

•Curtain of cloud to the ground around tornado

•Moved from Headingly to Elie just south of the highway

•Destroyed 4 -5 houses

•~ 40,000 people drove in from the area to see the damage afterwards

Hurricane, typhoon, cyclone

•3 names, but same phenomenon

•Atlantic: hurricane

•Pacific: typhoon (from Greek mythology)

•Indian: cyclone   ( “         “           “       )

•It starts over a warm ocean with a min. temp. of ~ 27 degrees

•Used to start AFTER June 21^st

  (forget it now, all rules have changed)

Features

•Strong wind

•There is an “eye” with extremely low pressure (like a vacuum)

•Heavy rain esp. around the eye

•Huge spiral cloud reaches to top of troposphere

•Causes “storm surge”, like a huge wave – up to 10 m high- that hits the shore on the right side

•Name picked from prepared list of local names

•The phenomenon is a huge engine powered by the latent heat of condensation

•It transfers the heat from the equator to the north and south & brings much needed rain

•minimum wind speed ~114 km/h

Hurricane near B.C. ?!

•Watch out young millionaires of BC!

The “bomb”

•Looks like a hurricane, but appeared on land (not water)

•It is an extremely low pressure phenomenon, a first in the world?

•Make out a name for it!

Water Resources

•Most countries have water shortage

•Warning issued last week from Iraq that the next war on Arab lands would be about water

•Canada, Sweden : only countries with ample water supplies

Only 3 % is fresh water

•Oceans have 97 % of water, but is salty

•No.1 source of fresh water is glaciers

•No. 2 is groundwater

•No. 3 is the “Great Lakes” & Lake Baikal

•No. 4 is all rivers & other lakes

Aquifers & water table

•Most people in Canada can get groundwater in a layer of sand /gravel/fractured rock

•This water-bearing layer is the aquifer & water flows downhill very slowly

•Need to drill a well to access it

•Rare below 600m depth where the pressure closes all openings

A water tower in a community

•Brings water to all houses by gravity

•Replaced by pumps in some places

“Arctic” means “bear” –in Greek

•So, is “ Moskwa” – in Russian / Cree

•“Antarctic” means “opposite the arctic”

•When you go north, this is the main problem, running into a bear

5 climates in classification

•Tropical

•Arid

•Mesothermal

•Microthermal

•Polar & high mountains

Climographs

•Variations in temperature over the year

•Variations of precipitation over the year

•Also,

•Not in the lab: variations of POTET, potential evaporation

•All the above can define the climate of an area

Tropical

•At or near the Equator

•Min. temp. of 18 degrees

•No seasons

•Rain by convection (air heated by sun)

•“malaria belt”, “bacteria belt”

•Plants / animals thrive, 40% of Earth’s C

•No soil, trees have no rings

•Unique fruits, vegetables, nuts, spices

Arid

•Deserts: most widespread climate on Earth ( arid & semi-arid)

•High pressure, cloudless, rare rain/snow

•Temperature varies

•Called steppes, pampas, veld

•Some life (underground during the day)

•Camel is like a water tank, froths when it overheats

Mesothermal (medium heat)
temperate, mild

•35 to 45 degrees N / S or near the sea

•No freezing (temp. above zero) moderated by the sea

•Rain/snow from air collisions

•Unique fruits/ vegetables / nuts / spices

  - citrus, olives, grapes (wine), figs, 

     sesame, carob

Microthermal (little heat)

•45 to 60 degrees N & S

•Coldest below zero

•Rain/snow from air collisions

•Boreal forest (taiga in Russia), short & tall grasses in Canada (grasslands elsewhere)

Can be severe (word comes from Siberia) on land away from the sea

Polar & high mountains

•60 degrees +,  N / S

•High pressure, rare rain/snow

•Like deserts

•Warmest month below 10 degrees C

•Tundra

•Large mosquitos / flies

•“Tree – Line”  & permafrost

Best climate ?

•In Greece (Hellas) : mesothermal

•On the sea, but dry because warm air from the Sahara desert blows over the sea (used to be zero humidity?)

•Rare clouds

•Clear skies make observations of natural phenomena easier to see

(don’t have to run away from rain & hide in a pub like they do in most of Europe)

Some of human accomplishements that started there & spread all over

•Language, literature, theatre, poetry, science, astronomy, medicine, engineering, calculus, geometry, democracy, the “oracle”, athletics (the Olympics), etc. etc

•Due to poor soil people migrated from thousands of years ago all over : Europe, N. America, S. America, Asia , Australia, Pacific islands all the way to Rapa Nui

Coasts

•West coast of continents are warmed by Gulf Stream, Japan Stream that flow clockwise, so no freezing in winter

•Examples: Scotland, Ireland, BC,

                     Alaska

 - East coasts may freeze : Labrador, Siberia

From previous slide

•Dramatic increase in CO2 have led to

•Dramatic increase in temperature

•Called Global Warming or Climate Change ( everyone has to respect environment & don’t blame it for its power, sometimes it kills)

Heating of oceans causes violent weather

•Results in more evaporation, more power in the air more storms & more extreme phenomena

•Just last week: tornadoes hit (prob. for 1^st time) in Berlin, Perth, New Zealand, Spain & Grand Rapids

•Severe storms, flooding with evacuations, fierce winds reported this year in numerous places

•These are entirely new phenomena, never observed in human memory

Topographical maps

•Contour lines: lines of equal elevation

•Help you to see in 3D

•Relief : highest elevation minus lowest

•Townships: 10 km by 10 km

•Direction of ice: predominant orientation of lakes in the area

•Electricity lines: power comes from the north in Manitoba

SECOND HALF   of  COURSE

GLACIATION

•Louis Agassiz from Switzerland

•French-speaking, so most names are French

•“Glace” is French for ice (crème glace)

•‘Glass’ is taken from “glace”

•Mr. Agassiz came to Canada and concluded that Canada had been under an Ice Age, too

•Last glaciation from 2 m.y. ago to ~ 10,000 years ago

Reason for an Ice Age

•Don’t ask, no one knows

•It prob. has to do with the gases in the air

•If there is too much CO2, the air gets warmed up (no chance of an Ice Age now, but can’t be 100% sure)

•If there is too much SO2, it reflects back heat, therefore, it is possible to get an Ice Age

•SO2 comes from volcanoes, therefore, a big eruption can trigger an Ice Age

65,000,000 years ago

•An asteroid hit Mexico in an area with lots of gypsum (calcium sulfate)

•The huge explosion released tremendous amount of SO2 into the air that blocked sunlight for years

•The planet froze, plants died, therefore animals who depended on plants died out too

•That is how the dinosaurs & others disappeared for good

•Glacier = a river of ice, needs a thickness of ~ 18 m before it can start moving

•Agassiz called it “God’s Great Plough”, like a bulldozer

•Glacier can be in mountains (alpine) or over continents (continental)

•Gives rise to specific landscapes

•It is due to the landscapes that Agassiz concluded that they formed from ice

Method of sculpting: beware!

•Abrasion

•Glaciers are 2 – 3 km thick, but it is not the bulk of the ice that breaks up hills & mountains on land as it moves

•Water at the bottom of the ice pile goes in small cracks in the rock below and expands into ice

•When water freezes it expands ~ 10 % & breaks the surrounding rock

•So, the breaking up of rock takes place silently UNDER the ice

Evidence for glaciation in Canada

•Flatness of land

•Shallow lakes in depressions, where bedrock was soft (water could not go away due to flatness)

•Smooth, polished rock surfaces

•Glacial till (stones of all sizes in the soil) left after ice melted

•Erratics (large rounded boulders)

•Specific landforms for alpine / continental glaciers

Erratics

Direction of ice flow in Canada

•Lakes lined up indicates direction of flow

•Thickest pile of snow/ice over Hudson Bay

•Bay depressed by the load of ice (not deep)

•Bay rising today slowly after load taken off (ice melted)

•From N to S in Manitoba, local variations

•Ice moved from E to W, north of the 60^th parallel

Extent of the ice

Alpine landforms

•Glaciers flow downhill into the sea

•U-shaped valleys with tributary valleys

•Horn : pyramid-shaped top of mountains

•Arete : sharp-edged ridge between adjacent valleys

•Hanging valley with waterfall

•Fjords : where U-shaped valleys flooded by the sea, the most spectacular scenery

Horn

U-shaped valley

Alpine glaciers in valleys

Alpine glaciers in valleys

Hanging valley

Fjord

Preikestolen

Icebergs

•Only place to see them floating in the ocean is Newfoundland (& Labrador)

•They come into the sea at the southern tip of Greenland

•They are pushed by the current up the Gulf of Baffin and down along east coast of Labrador & north coast of Nfld

•They melt south of Nfld when they meet the Gulf Stream, a few km south of the Titanic disaster

Continental glaciers

•Esker : river below glacier

•Kame / kame terrace : river above glacier

•Moraine : glacial till where glacier stopped

                      The Manitoba “mountains”

                      The Pas Moraine

 - Polished rock surfaces: roche moutonnee

 - Drumlins : oblong hills of till, usually in groups
 - Striations on polished rock surfaces

Eskers, kames terraces, Ice Flow in Manitoba

Esker, Kame Terrace, near Thompson, Drumlin

Permafrost country

•Landscapes formed by repeated freezing / thawing of the ground

•Soil “turning around” continuously, moving structures on the surface

Effect of permafrost, Soil flux (moving), Palsa: organic material, drunken forest

•Patterned ground

•Pingo

•Frost shattering, rock burst

KARST

•Limestone / gypsum on the surface can be dissolved by water (water is a bit acidic)

•Drainage moves underground (streams, rivers, lakes)

•Limestone from Winnipeg to The Pas along the Interlake

a sinkhole, Cenote

Karst terrain, Guilin, China

Stone forest, China

Caves, Vietnam

Bahamas (means shallow water) Banks

•Limestone with caves, sinkholes

•The rise in the sea level sank those caves far below water

•“blue holes”

LANDSLIDES

•Mostly in the mountains

•Everything on the slopes is unstable (gravity)

•Slopes more the 33 degrees (angle of rest) slide

•Only the roots of trees can keep soil in place

•Grass, bushes not enough

•Development of all kinds (houses, roads, etc starts with clear cutting, therefore vulnerable)

Half of landslide disasters in Canada

•Are in the mountains

•Worst disaster at Frank, Alberta, 1903 under Turtle Mt., locally known as “Rumbling” Mt. 77 died, museum along No.3 Hwy.

•Coal  mine underneath, torrential rain may have contributed

Surprise !

•Quick clays in Quebec have ½ of landslide deaths in Canada

•Clays formed in the ocean & salt component has dissolved leaving open spaces in the soil

•Easy to trigger a landslide in such a soil

•A heavy truck on the road, heavy rain, etc

RIVERS

Delta & Estuary: Mouths of rivers: end of a river

•Most have a delta with sand deposits, like the Nile, Mississippi, Mackenzie (Deh Cho), Red river (Winnipeg beaches)

•Some have an estuary, prob. because the tide won’t let the river drop its sand above water level. Examples are the Amazon, St. Lawrence (Kaniatarowanenneh = big waterway)

Watershed

•A river with its tributaries & smaller streams makes up the Drainage Basin, or watershed

•The river channel is V- shaped, can be deep

•The river has a floodplain that it occupies during the spring or summer floods with natural terraces (levees) of sand/gravel/clay

•The river deposits nutrients that plants need along its floodplain, that is why it is productive

Continental Divide

•Separates watersheds that flow in opposite  directions

•For example there is C.D. that separates Manitoba rivers (flowing north) from the Mississippi river system (flowing south)

•Sign says “ from here all rivers flow north”

•On the other side: “ from here all rivers flow south”

Alluvium

•The river brings gravel, sand along the bottom and lighter clay in suspension (what makes the water dirty-looking)

•All these sediments are called alluvium

•The amount of water in the river is its discharge (= depth X width X speed)

The mouth of the Amazon

Muddy but clean water

Meandering rivers (like Assiniboine)

•When the topography is flat, the river zig zags across the floodplain

•In a bend, its outer bank is undercut (gets deep) by faster water while its inner bank is slow with the river depositing sediment in a point bar – a place to look for gold, diamonds

•Loops of the river can be cut off & form oxbow lakes ( like at Portage La Prairie)

Portage La Prairie

Red River

•Most frequently flooded river in Canada

•Problem probably because it flows north across various climates

•Winnipeg protected by the Floodway that brings water around the city instead of going through the city

•Portage Diversion takes the water from the Assiniboine into Lake Manitoba (which flooded last year), so it will not flood Winnipeg

The “Red Sea”, 1997

Drainage in Manitoba

•Lowest elevation roughly stretches N-S in the middle of the province

•Water from the Red river empties into Lake Winnipeg and flows north along Nelson River into Hudson Bay

•Winnipeg river and Saskatchewan (Kisiskaciwani sipi = swift flowing) river flow into Lake Winnipeg

Nick Point

•Rapids, an irregularity in the slope of a river

•The water works to eliminate the nick point which retreats up-stream

•Hydroelectric dams built on nickpoints where the falling water is used to turn a turbine lined with magnets, thereby creating electricity

First Hydroelectric Dam- in the world

•Built at Niagara Falls

•Statue of Tesla there: responsible for inventing every electrical device that we use

•Big business ‘stole’ his invention

•Nick point has moved 12 km upstream from the Niagara Escarpment (a rise in the land elevation) creating a deep canyon

•Part of the St Lawrence Seaway

The “Great Lakes”: part of the St. Lawrence Seaway

Other rivers

•Nile : longest

•China’s longest: Yangtze

•Widest : Indus (= son of God)

Thames, London, UK: only river with gates to prevent flooding (if the sea water moved up-river

DESERTS: God of wind is in charge Aeolos

•“Evaporation exceeds precipitation”

•Hot or cold (Antarctic)

•Sand covers only 20 % & is in constant move

•Sand accumulates in dunes (steep slope is down-wind)

•Erg is a sand sea

•Many shapes of dunes, most common a barchan

Barchan dune: wind from the right

•Oasis :depression with spring water often below sea level

•Animals / humans can suffer from dehydration

•Slim chance of survival if unprepared

•Taklimakan: “once you go in, you can never come out (alive)”

•Kalahari: has a “skeleton coast”

•Atacama: world’s driest place

•Sahara: largest desert

New idea?

•There is no rain in the desert, because there are no plants!

•If enough plants are planted, evaporation could form clouds & rain

•New plantations in the Sahara & Middle East –with water drawn from deep wells - may reduce size of desert

Soluble salts

•Normally would be dissolved in water

•Boron, salt, gypsum, sodium sulfate (detergent), sodium nitrate (explosives), potassium nitrate (toothpaste), lithium (batteries) lying about on the surface

Playas (dried up lakes)

•More than 100 in N. America

•Have encrusted salt (after water has evaporated)

•Excellent racetracks, runways for planes, spacecraft (used by military, some are notorious for secrecy & biological experiments, such as Area 51)

Athabasca Sands

•Northernmost dune field in the world

•Sand blown from bottom of dried-up lake Athabasca during Ice Age

•Buried some of the forest and keeps moving to the SE with the wind

Dead Sea

•Along the Jordan river, no exit to the sea

•Lowest place on the planet, 422 m below sea

•Salty water makes it possible to float on water

•35 % salt

•World’s first health resort (visited by Cleopatra)

•Lake Watrous, Sask. is similar

Sandblasting

•Wind can move sand in the air

•Erodes exposed rocks and shapes them aerodynamically - yardang

Desert Pavement

•Gravel on the surface

•Don’t walk or drive over it!

•The disturbance would release the sand from below

•This would cause another sand storm!

Dust storm over the Atlantic

Loess

•Worldwide deposits, but not in Canada

•One of the best soils, spade marks visible for years, roof won’t cave in, rich in organic remains

•80% silica, 10 % carbonates & phosphates

•Yellowish -colors the “Yellow river” in China, also gives name to the “Yellow race”

•Probably formed outwash of glaciers

Uluru, Australia

Just before  sunset

Dramatic change of color

Wave cave

Method of sculpting

•Forms at the bottom of the Uluru rock

•Sandstorms are common with sand from the desert blasting a hole into the rock and shaping it like a wave

COASTAL

•Erosion by waves

•Movement of sediment by currents depositing off the shore and forming “barrier islands”

•Longshore current: current along the shore

•“Killer waves”: esp. in peninsulas. Waves tend to eliminate peninsulas, so they converge on them with combined force

Sea level rise

                   - During last Ice Age was 120 m lower

     Natives of Chile: “people arrived when sea was lower, then the sea rose and the peninsula (Chlh in ancient Greek) became an island”  (today the island is known as Chiloe, also, the name of the country)

    3,000 BC to 1,900 AD: no change

•1900 – 1992: 1 – 3 mm / year rise

•Since 1992: up more, variable, no agreement

Predictions

Predictions as good as yours: no one knows!

-A 4 m rise will flood most of Florida

-The Dutch (whose country is mostly below the sea) are prepared for a 7 m rise with massive fortifications

-Australia gave orders to ~ 100,000 home owners to move away from coast – insurance /the country will not pay to relocate them!

The “sinking islands”

•Paradises under threat, mostly atolls in the Pacific Ocean

•Used to be volcanoes that became inactive

•Erosion destroyed volcano, coral reefs formed around the island (due to warm, tropical conditions), then all that was left was a strip of land like an arc with shallow water in the middle (was the old, eroded volcano)

•Shallow water inside with deep water outside the arc of land. Barely 1 – 2 m above sea level

Pacific Ocean

•Polynesia (ancient Greek for “many islands”)

•Melanesia (    “          “       “     “black islands”)

•Micronesia (    “        “       “     “small islands”)

Pacific Island countries

•Kiribati

•Marshall Islands (includes Bikini )

•Fiji

•Tonga

•Vanuatu

•Nauru (voted the happiest place on Earth!)

•Tuvalu

Most have schools built by Canadian Government, volunteers urgently needed! (includes free fare)

Salty seawater: what is in it?

•The results of weathering of rocks

•98% of the “salts” have these 7 elements:

•Sodium

•Potassium

•Calcium

•Magnesium

•Chlorine

•Bromine

•Sulfur

Tides: a powerful phenomenon

Tides: “the heartbeat of our oceans”
“the voice of the moon”

•Only in big oceans (not in Hudson Bay, Mediterranean)

•“pull” by moon, also the sun as they go around the planet (so, it is just gravity)

•From 30 cm to 1.5 m

•Highest at Bay of Fundy, Nova Scotia (up to 16 m high between low & high tide)

•It is a RESONANCE affair!

Resonance

•Push a child on a swing to learn about resonance

•It is like the max. speed. Once you get it, one can push one-shelf further.

•“Tendency to oscillate with a greater amplitude at a certain frequency than any other frequency”

•Resonance depends on weight of person

•So, basically how fast a body of water will swing, when the moon’s gravity acts on it

•            It depends on depth of water, how smooth the bottom is, etc

Tidal Day: 24 hours 50 min

•Like a lunar day

•If you keep watching the moon at the same time daily, it gets a little bit behind every day

•Two high tides & two low tides per day

•12 hours 25 min between two high tides

•~ 6 hours between a high and a low

Bay of Fundy

•“World’s largest bathtub”, funnel-shaped

•Tides established here only 6,000 years ago

•Water moves in & out of the Bay in sync with the tide à the tide gets amplified

•Average tide ~ 1 m

•Silt, sediment & nutrients move in & out twice daily, therefore LOTS of MARINE LIFE : lobsters, crabs, clams à birds, whales

Cape Split

•Narrow peninsula sticks towards the Bay

•In front of it pass 14 b. tons water, equal to combined flow of all rivers /streams in the world

•Hollow roar when turbulent water smashes on rock caves below

•3 hours later the spectacle pauses & starts again flowing in opposite direction

St. John River, New Brunswick

•The “Reversing Falls”: ‘confused waters’

    due to tide moving up the river (if it is higher than the level of the river)

  - a daily battle between the tide and the river

Tidal bore

•Bore: Swedish/Norwegian word for “thunder”

•A wave moving UP the river (due to tides)

•Can be heard coming from far away with a loud noise (sound of an approaching train)

•It is like a shock wave

•Only observed in 60 rivers of the world with waves up to 10 m high

•Good for surfing, rafting moves at 15-20 km/h

Pororoca, on the Amazon

•Earth’s greatest (or longest) wave

•Name means great destructive force

•Can uproot trees from the riverbanks

•Conditions: has to have large tidal range in the estuary & river bed has to slope gently towards the sea

•The bore is the reason Amazon has NO delta

Tombolo

•Island close to the shore can slow down water currents and accumulate sediment

•Eventually it forms a causeway linking island to shore

•Gimli, Manitoba: used as a harbor

Other phenomena

A lesson from Peru

•In the mountains, people lost their glaciers and they get very hot summers – don’t like neither do their animals

•They painted their mountain WHITE

•The glaciers are coming back

•Won an International Award