Geography of the Middle East

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Transcript Geography of the Middle East

Chapter 2: The Face of the Earth
A) Physical environment influences human activities:
- modes of living
- urban development
- transportation
- energy sources
- access to irrigation water, etc.
B) Environmental factors interact with each other:
- precipitation & vegetation
- elevation & temperature
- bedrock & soils, etc.
- Factors of climate, geomorphology, geology, etc. have effects on
cultural and economic patterns.
- A better understanding of these patterns will help us to explore
historical, economic, and social patterns in the Middle East.
Landscape in Oman
Landscape in Iran
Palestinian children
Oasis in the United Arab Emirates
I) Forms of the Lands
Four Land Areas
1) Asia Minor embracing Anatolian Plateau in the NW
2) Iranian Plateau extending into Asia Proper
3) Arabian Peninsula along axis of Red Sea plus Egypt
4) Fertile Crescent as the regional hub
Five Water Bodies
1) Mediterranean Sea
2) Black Sea
3) Caspian Sea
4) Persian Gulf (as an extension of the Arabian Sea)
5) Red Sea
- Seas intersperse moisture into desert areas
- Seas as created opportunity for human contact, trade
& movement of peoples
Amasra (Turkey) on the Black Sea
Satellite image of the Black Sea
Satellite image of the Caspian Sea
Baku (Azerbaijan) on the Caspian Sea
Town of Lāft (Iran) on the Persian Gulf
Sandstorm over the Persian Gulf
Sharm el Sheikh, Sinai Peninsula (Egypt), Red Sea
Satellite image of the Red Sea
Major landforms of Middle East caused by Plate Tectonics
- Tectonics of 4 to 6 plates in the Middle East have created
present patterns:
- seafloor spreading & rift valleys
- subduction and collision zones
- folding, faulting, pulling apart
- earthquakes & volcanoes
- major fault zones of Anatolia and Iran
- upfolded mountain ranges (i.e. Zagros) and downfolded
troughs (i.e. Persian Gulf)
- rift valleys (i.e. Red Sea)
Elburz Mountains and Caspian Sea
Mount Ararat and Christian monastery
Different aspects of plate tectonics
In addition, local forms have been shaped by other factors
- weathering
- erosion by water and wind
- deposition of eroded materials (sand dunes, alluvial
fans, deltas, etc.)
- local tectonic events (volcanism & earthquakes)
- desert pavement
- work of streams in earlier geologic times
Nile Delta and the gulfs of Suez and Aqaba
Sand dunes in Saudi Arabia
Alluvial fan at the foot of a mountain range
Cappadocia (Turkey) eroded chimney rocks
The three general landform provinces of the Middle East:
I) Stable Interior Province
II) Mobile Belt
III) Median Trough
Topographic and tectonic features of the Middle East
Three general landform provinces
1) Stable Interior Province
- Nubian-Arabian Shield
- Nucleus of the Stable Interior Province
- plateau with volcanic features, faults and ridges
- seafloor spreading created Red Sea
- covered by thick sedimentary rock, some of which
contain oil reservoirs
- Arabian Peninsula
- coastal plain of Tihamah along Red Sea
- Hijaz Mountains
- High Yemen as result of lava flows through fissures and
vents created by Red Sea Rift
- sedimentary rock in area of Arabian Shelf contain oil
- deserts (Rub al-Khali, Nafud, Dahna)
- Oman Mountains as result of collision between
Arabian Plate and Iranian subplate
- Egyptian Deserts
- Eastern Deserts (between Red Sea and Nile) plus the
Red Sea Hills
- Western Deserts west of Nile
- Nile River flowing between both deserts
- series of 5 oases along contact between two sets of
sedimentary cover
- Central Areas
- more level with undulating surfaces
- same general sedimentary sequence
- Jordan Valley & Related Features
- Levant Rift System (transform fault)
- Gulf of Aqabah, Dead Sea, Sea of Galilee, Huleh Basin
- highlands formed by upfolding and faulting
- Judean & Samarian Hills, Galilee Highlands,
Mount Lebanon, Jabal al-Nusayriyah
Top: Fayyum Oasis
Left: Oases in Egypt along the contact
zone between sedimentary layers
of different thickness.
2) Mobile Belt
belt of folded, faulted, compressed mountains
Asia Minor and Cyprus
- Pontic Mountains north of North Anatolian Transform Fault
- slippage and earthquakes (August 1999)
- Taurus Mountains on southern side of Asia Minor
- Anti-Taurus Mountains extend eastward (to Zagros Mnts)
- East Anatolian Fault parallel to Anti-Taurus
- mineralization along zones of lava flows
- Aegean coastal zone as area of “horsts” and “grabens”
- Cyprus formed due to same plate collision as Taurus range
Iranian Plateau and Ranges
- compression, subduction between Arabian plate and
Iranian subplate
- creation of Zagros Mountains
- Makran Range farther SE as uplifted crust
- upfolding of Elburz Mountains and Kopet Mountains
between Iranian subplate and Eurasian plate
- connected tectonic activity and volcanoes
Anti-Taurus Mountains
Taurus Mountains
Pontic Mounatins
Elburz Mountains
3) Median Trough
- Mesopotamian / Gulf trough lies along axis between
Arabian plate and Iranian subplate
- zone of subsidence and downbuckling along flanks of
Arabian Shield
- zone of immense petroleum reserves!
- NW half of Mesopotamian Basin is above sea level
- SE half is drowned by waters of the Gulf invading from
Indian Ocean through Strait of Hormuz (important
economic and strategic chokepoint)
Mesopotamia
Golf of Hormuz
Oil infrastructure centered on the Persian Gulf
I)
Middle East Waters
1) Seas and Gulfs
- major modifications in response to crustal adjustments
and climatic variations
- during Pleistocene sea level fell more than 395 ft.
- during same period Middle East was more moist, inducing
favorable conditions for cultural development
- great drop in sea level left straits of region dry
- Gibraltar, Bosporus and Dardanelles, Hormuz
- cut off from water, basins of some inland seas dried out
A) Red Sea and Gulf of Aden
- tectonic extension of African Continental Rift
- Gulf of Aqabah, pull-apart zone assoc. with Levant Rift
- Rift of the Gulf of Suez
- Gulf of Aden created by seafloor spreading
B) Persian Gulf
- lying in a tectonically downfolded basin
- wide variation of temperature and salinity
- major fresh water influx through Shatt al-Arab
- during Pleistocene, Euphrates-Tigris system
emptied into Arabian Sea through Strait of Hormuz
- major oil export terminals in Gulf
- 40-50 large tankers per day through Gulf
- environmental problems and pollution crisis of 1991
- impact on fishing industry and flora and fauna
C) Mediterranean Sea
- complex origin (area of old sea plus collapsed structure
along collision zone of African and Eurasian plates)
- virtually enclosed; narrow Strait of Gibraltar
- Suez Canal as artificial link (since 1869)
- extensive, deep waters of Mediterranean (more than 4,700
feet near Crete)
- impact on climate in Middle East and North Africa
- maritime cultures (diet, fishing, music, trade)
D) Black Sea
- major importance to states that fringe its coasts
- shallow near Danube Delta / exceeding 7,000 ft. in south
- slopes of Pontic Mountains plunge into Black Sea
- deep water ports in northern Turkey
- receiving plentiful freshwater; moderately salty
- virtually tideless
- overflows through Bosporus into Sea of Marmara
and then through Dardanelles into the Aegean Sea
- Black Sea states try to concert env. and econ. planning
E) Caspian Sea
- inland “sea” without outlet / surface 92 ft. below sea level
- most of inflow from Volga / sea level dropping due to
utilization of Volga and other waters for irrigation
- freight, ferries, passenger ships and fishing boats
- as with Persian Gulf, tectonics that created Caspian
Sea were favorable for huge accumulations of fossil fuels
- prior to 1991 negligence in protecting the environment
2) Rivers Great and Small
- extreme aridity in large areas of Middle East precludes largescale local runoff
- major rivers in area rise in highland regions of significant
water surplus (exotic rivers!)
- structural conditions divert considerable interior runoff into
closed basins
- thus major river systems in Middle East are limited in
comparison to other world regions
- two largest systems are Nile & Euphrates/Tigris
- all three rivers cross deserts for hundreds of miles
- disputes between countries and ethnic groups over water
access and control
- in Arabian Peninsula no perennial streams (ephemeral
streams!)
- with exception of the Nile, all Middle East rivers have a
maximum runoff in late Spring
A) Tigris and Euphrates
- both come from eastern Anatolian highlands in Turkey and
enter Gulf through Shatt al-Arab
- they lose water as the cross flat deserts and their waters are
diverted for irrigation
- > 90% of actual water is flow from runoff in Turkey
- Euphrates is longer, but Tigris carries 25% more water
- increasing diversion of Euphrates by Turkey and Syria
- diversion of Tigris waters via Lake Tharthar to Euphrates
- Iraq’s “third river” from Baghdad to Basrah (in 1992)
B) Nile River
- world’s longest with 4,240 miles, draining one tenth of Africa
- masses of water traverse the full width of the Sahara Desert!
- completion of Aswan High Dam in 1971 greatly altered the
rivers regime (Lake Nasser)
- White Nile from Lake Victoria into Sudd, joining Blue Nile (from
Lake Tana) at Khartoum
- Blue Nile is fed by monsoon rains of Ethiopian Plateau
- fluctuations of Blue Nile formerly led to famous floods in Egypt
- series of 5 cataracts / creation of the delta
C) Fold Belt Rivers
Asia Minor and western Iran have many perennial streams
- Büyük Menderes (SW Anatolia)
- Gediz (N of Izmir)
- Sakarya (between Ankara and Istanbul)
- Qezel Owzan-Safid (between Tehran and Tabriz) etc.
(most of the Anatolian rivers have been dammed)
D) Three Levant Rivers
- Jordan River (draining SE Lebanon, SW Syria, and N Israel)
(importance and consequences of irrigation!)
- Litani and Orontes empty into the Mediterranean
3) Middle East Lakes
- few natural lakes of considerable size in the Middle East
- noteworthy lakes are:
- Sea of Galilee (religious and historical significance)
- Dead Sea (1,310 ft. below sea level; 35% salinity; no fish;
evaporation pans)
- Lake Urmia and Lake Van (Iranian – Turkish border)
4) Groundwater
- in addition to surface waters of vital significance Middle East
- some natural springs (mainly as artesian wells)
- other water is tapped by hand-dug wells
- in Iran water in alluvial fans is tapped by qanat system
- oases in deserts may be supplied by river water, natural
springs or dug wells
- although large (fossil) groundwater supplies exist in the
region, exploitation has strained these water supplies
- critical shortages will develop in coming decades
- saltwater intrusions?
Lake Van (Turkey)
Lake Urmia (Iran)
Qanat System in Iran
In sum, significance of the patterns of physical geography in the
region goes beyond that of simple landforms:
Influence on and interaction with cultures:
- settlements
- transportation routes
- agricultural potentials
Influence on and interaction with the environment:
- climate
- soils
- vegetation
Particularly water (and oil) though are critical and highly
contested resources in the Middle East.
III) The Skies and the Winds: Climate
Climate has as much direct and indirect impact on people
and their geographic factors as any geographic factor:
- human habitation
- clothing
- architecture
- agriculture
At the same time, temperature, precipitation and winds influence
other natural elements:
- vegetation
- soils
- landforms
- animal life
In turn, temperature and precipitation are influenced by:
- elevation
- mountain barriers
- large water bodies
Understanding weather and climate in the Middle East
Basics: Earth-Sun Geometry & Latitudinal Position
Understanding weather and climate in the Middle East
Basics: Global Atmospheric Circulation Patterns
Understanding weather and climate in the Middle East
Basics: Causes for Rain
Orographic precipitation
Convectional Precipitation and the ITCZ
- rising air masses over heated surfaces
- the Inner-Tropical Convergence Zone (ITCZ) and according
trade winds in the summer and winter of each hemisphere
Understanding weather and climate in the Middle East
Basics: Global Average Precipitation Amounts
Understanding weather and climate in the Middle East
Basics: Global Climate Zones
A) Factors of Middle East Climates
- difference between climate and weather?
- six basic factors in the Middle East control the climate
1) Latitude
- determines the angle at which sun rays strike the earth
- as sun “migrates” between the tropics of Cancer and
Capricorn, global atmospheric circulation patterns shift
- for general discussion, the 35th parallel divides the
Middle East into more humid north and arid south (3/4 !)
(except some small coastal and high altitude areas)
2) Seasonal Pressure Belts
- atmospheric pressure influences whether air is
descending or rising (clear skies vs. potential rain)
- pressure in adjacent belts determines the strength,
direction, duration of winds in a given area
- main pressure belts affect the Middle East weather conditions:
a) subtropical high pressure belt (S of 35th parallel)
- high pressure belt and dry NE trades produce deserts across
N Africa, Middle East, Central Asia (Arabic sahra = desert)
b) more humid areas (N of 35th parallel)
- from Aegean and Mediterranean Seas to Northern Iran area
of typical Mediterranean Climate
- hot, dry summers and cool, moist winters (compare to
southern California)
c) Monsoon in SE Middle East
- results from seasonal reversal of great Asian pressure
systems (high pressure in winter, low pressure in summer)
(Arabic mawsim = season)
- bringing critical precipitation to parts of Yemen and Oman
3) Passing Pressure Systems
- passing pressure systems as winter weather makers
- shift of atmospheric circulation belts to south in the Fall and
Winter bring stormy westerlies and rain to Asia Minor,
Lebanon, Syria, Iraq and Iran
4) Land-Water Relationships
- sea as ultimate source of all moisture so that presence of large
water bodies increases potential for higher humidity and
precipitation in addition to modifying temperatures in general
- Maritime vs. continental locations
5) Landforms
- topography influences every aspect of climate
- highland areas have lower temperatures
- mountains intercept winds and wring moisture from them
- orographic precipitation (e.g. slopes of Mount Lebanon)
- similar in Anatolian, Zagros, Elburz & Yemen Mountains
6) Ocean Currents
- currents off the coasts can also significantly modify climate
Precipitation patterns, soils and vegetation types of the Middle East:
B) Elements of Middle East Climates
Factors just reviewed produce various climate characteristics
within regional climate types (desert, steppe, and humid temperate)
1) Temperature
- high temperatures prevail more than half the year in most
lowland areas of Middle East
- Abqaiq in east Saudi Arabia shows maximum temperatures
July – October from 110 – 125 degrees F
- before installation of AC units, houses in Middle East often had
underground rooms (sirdab) in which people sought relief
- in low-income neighborhoods in cities such as Cairo, people
might sleep on the flat roof of their Houses
- in open deserts and at higher elevations, temperatures can
drop to the lower 40’s and beyond, bringing some respite
- mountain areas as prosperous summer resorts
- degree of temperature contrasts between summer and winter
depends primarily on latitude, interior location, and elevation
2) Winds
- can move sands (sand dunes)
- can be used by sailing vessels (trade winds)
- monsoon winds in Arabian Sea (NE in winter, SW in summer)
- strong NE trades in Aegean and Mediterranean Seas
(e.g. sailing up the Nile River on faluqas)
- shamal (“North”) winds of Arabian peninsula in early summer
(sand storms) determined time of “Desert Storm” in Jan. 1991
3) Precipitation
- significance of precipitation must be emphasized
- high seasonal temperatures in much of the Middle East typically
accompany low seasonal precipitation
- thus, dryness is the keyword for much of the region
- interior southern half of Arabian Peninsula < 1 inch per year
- some areas in northern Middle East receive 15 to 40 inches
- with few exceptions, most rain falls October through April
- precipitation in deserts on average very low but vary greatly
- precipitation events depend on latitudinal position and
orographic situation
4) Humidity
- three generalizations:
- low humidity characterizes deserts and high elevations
- humidity along coasts, even in arid areas, tends to be high
- humidity is moderate and exercises no remarkable effects in
much of Asia Minor
5) Evaporation
- evaporation plays a key role in determining aridity
- evaporation hard to measure; but natural vegetation is
indicative of aridity and indirectly of evaporation
C) Climate Regions of the Middle East
- nearly half of the Middle East is BW (desert) climate
- another 18-20% is BS (steppe) climate (nomadic herding on the
dry side / cultivation of barley and even wheat on the moist side)
- another third of the Middle East is Cs (Mediterranean) Climate
(hot, dry summers / cool, moist winters)
- small but negligible areas of Cwa (S- Oman) and Cfa (coastal Black
Sea) climates
IV) Soils, Vegetation & Animal Life
- soils are the product of several environmental factors:
climate, parent material, vegetation, fauna, relief, time
- importance for agriculture
- vegetation of an area is indicative of the general character of
local precipitation, temperature, soil, animal life, pressure of
human populations, and other aspects
- xerophytic plants
- variety of Middle East environments supports a rich fauna
- Iran alone has approximately the same number of species
of mammals as all of Europe
- still, in some areas animals have been reduced to a fraction
of their former count, may be nearing extinction, or have
disappeared altogether
(e.g. lions, tigers, crocodiles, wild boar, deer, gazelles)