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Malnutrition – the body’s
response to a lack of food in terms of the calorific energy
intake or a lack of the right food in terms of the
proportions of energy, minerals, protein, and vitamins. Can
expose people to disease by weakening resistance, or kill
people through organ failure.
Malthus, Thomas Robert
– in geography, renowned for his theory of population as it
relates to resources. Based on the principles that food
production increases at an arithmetic rate, whereas
population increases at an exponential rate, Malthus stated
that population had to outstrip resources over time. He
suggested that this would trigger both preventative checks,
such as postponement of marriage or reduction of family
size, and positive checks, such as famine or war, to reduce
population. Unforeseen changes in technology and
agricultural organization discredited his theory as massive
food production increases through the nineteenth and
twentieth centuries negated his ideas. However, his theory
has found new favour in the late twentieth century as
neo-Malthusianism.
Mangrove swamp – a type of
wetland forest made up of salt-adapted trees found in the
inter-tidal zone of
tropical coast areas. Provide
a rich
habitat for strong
biodiversity and
help protect coasts from erosion.
Mann, P. – proposed, in 1965, a
model of urban land-use which integrated the ideas of
Burgess and
Hoyt into a single model for British
cities. The model was made up of concentric circles divided
into wedge-shaped sectors which allowed for the more
segmented nature of development and redevelopment in urban
environments in the real world.
Manning’s N – after Robert
Manning. A formula of river velocity:
v= R0.67
x S0.5
n
where R
is
hydraulic radius, S is channel slope and n is
Manning’s roughness coefficient.
Manning’s
roughness coefficient – after Robert Manning. A
measure of channel resistance which is used as part of a
formula to calculate velocity (Manning’s N). The
values vary between 0.02 for smooth channels and 0.10 for
very rough channels.
Mantle – the layer of the earth
between the crust and the core. The upper part is the
lithosphere (which includes the crust above). The
majority of the mantle is the
asthenosphere which
extends to a depth of 2900km. Mostly made of silicates, iron
and magnesium.
Manufacturing industry
– businesses that convert
raw materials into finished
products or component products, and those that convert or
assemble component products into finished products.
Map projection – the system
of representing the three-dimensional surface of the world
into the two-dimensional surface of a piece of paper.
Maquis – scrub vegetation made up
of plants such as heathers which can grow up to 3 metres in
height. It is found on areas of
impermeable rock in
Mediterranean regions where the original forests have been
cleared by humans.
Marina – a man-made dock or mooring
area, protected from the sea, particularly for the mooring
of pleasure craft.
Maritime – of the sea.
Maritime climate – the
climate of land areas in
coastal regions where the
characteristics of the climate are clearly affected by the
proximity to the water mass. For example, the UK has a very
different climate to continental areas at the same
latitude.
Market – can be seen in two ways:
-
a
place where goods and/or services are offered for sale.
-
the
demand for a good or service in an area from local to
global scale.
Market economy – one run on
laissez-faire principles.
Market gardening – highly
intensive (in
capital terms) farming of
flowers, fruit and very perishable vegetables on a
commercial basis. Usually located close to urban areas as an
immediate market, but large enterprises may also distribute
at national and regional scale.
Market town – a town whose
main
function is to act as a market place for the
surrounding area.
Marram grass – a species of
grass that is tolerant of dry, sand dune environments.
Important as a stabilizing factor in the development of a
psammosere.
Marxism – a political theory
and/or practice where the emancipation of the working
classes through class struggle is seen both as the driving
force of history and the goal of modern society. Developed
by Karl Marx and Fredrich Engels, and most famously
presented in their Communist Manifesto of 1848. In depth
analysis here:
http://www.marxists.org/subject/students/index.htm
Mass production – the
production of finished goods on a very large scale i.e.
large numbers of units coming from a single production
facility or factory.
Mass
movement – the downslope movement en masse of rock, earth or
water. For an excellent overview see:
www.fiu.edu/~longoria/natural/mass/mmain.htm
Material index: after
Weber,
MI= weight of raw materials needed to produce a unit of
finished product
the weight of a unit of finished
product
Meander – an exaggerated, looping,
bend in a river. Once formed, meanders grow in such a way
that they will eventually cut themselves off from the river
and cease to exist. Flow around the outer bend is faster
than on the inner meaning
erosion occurs there to
undercut the outer bank and material is moved across the
meander and
deposited on the slower inner bend. The
meander can therefore migrate across the land on which it
flows – usually a lower course
floodplain. Thus, over
time, the ‘neck’ of the loop closes until it joins and the
river takes the shortest route, cutting off the meander and
forming an
ox-bow lake.
Mechanical weathering
– see
physical weathering.
Mechanisation – the
replacement of human and/or animal
labour with
machines.
Mediterranean climate – climatic characteristics first
identified around the Mediterranean region but since
discovered to exist in the Cape region of South Africa,
central California, central Chile, and the parts of southern
Australia having a west facing coastline. Annual
temperature range is approximately 15˚C, with summers
being very hot and winters mild. Annual
precipitation
is 400-700mm, most of which falls during winter months. This
is the result of the ITCZ coming closer in summer and
squeezing the sub-tropical high pressure zone of descending
air into these areas. In winter, the movement of the ITCZ
away pulls the Ferrel/Polar convergence into these zones
bringing westerly winds and weather associated with
depressions.
Megalopolis – vast expanse of
essentially continuous built-up area created by merging
urban centres. Coined particularly in the U.S.A. where
urban sprawl has blurred the distinctions between
certain cities, e.g. BosWash: the extensive built-up area
from Boston, through Massachusetts to Washington D.C.
Meltwater – liquid water that
has come from melting snow or ice.
Meridian – a line tracing a
circle that passes through both poles.
Mesa – a flat-topped hill standing up
from a plain.
Mesosphere – the layer of the
atmosphere above the
stratosphere. Air temperature
once again declines with altitude.
Mesozoic – an era of geologic
time lasting from 245m to 65m years ago.
Metamorphic rock – rocks
created by the chemical alteration of existing rocks under
the influence of temperature, pressure, or both.
Meteorology – the study of the
atmosphere.
Methane (CH4) – a
naturally occurring gas which is associated with
decomposition and with oil deposits. It is a
greenhouse gas and burning it, or releasing it to the
atmosphere will lead to the creation of carbon dioxide and
water vapour, both themselves greenhouse gases. It is
therefore of great importance in
climate change.
Microclimate – the local
climate conditions that show variations to the general
climate conditions of the wider environment.
Mid-oceanic ridge – an
elongated range of undersea mountains formed by the
extrusion of
lava, combined with the upward pressure
of a
convection plume, at a
divergent plate margin.
Migration – properly, any
movement of a living organism across space, or between
locations. In geography, most commonly applied to population
movements. It can be used to describe daily and seasonal
movements (e.g. commuting and holidaying), but is most
usefully applied to movements lasting longer than one year.
Generally classified by motivating reason:
-
forced
e.g. poverty, war, famine.
-
voluntary e.g. looking for better work, education.
While
not definitive, forced migrations are usually made by large
numbers of people from the area suffering the motivating
factor whereas voluntary migrations are made by individuals,
though the motivating factor could effect a collection of
individuals from the same source area.
Milankovitch, Milutin
– proposed climate variations are due to variations in the
amount of
insolation caused by variations in the
earth’s orbit and positioning in space.
http://www.homepage.montana.edu/~geol445/hyperglac/time1/milankov.htm
Mining – extraction of minerals
from the
crust for industrial use.
Mist – a light fog. Visibility
usually remains beyond 1 kilometre.
Mistral – the French term for a
katabatic wind.
Mixed
economy – the most common form of national economic
organization, somewhere between a command economy and a
market economy. The degree of government intervention is the
basis of most political division in countries using this
system.
Moho – see
Mohorovicic
discontinuity.
Mohorovicic
discontinuity (Moho) – after Mohorovicic, the
junction between the crust and the mantle.
Monoculture – an agricultural
system in which the
cultivation of a single crop is
the norm.
Monopoly – control of supply of a
product or service to a particular market. In its pure form
this would mean a single supplier, but his rarely occurs.
Highly dominant suppliers can however exert monopolistic
controls in certain circumstances.
Monsoon – a seasonal
prevailing
wind. Two types:
-
summer
monsoon: intense heating of a continental mass in summer
months due to the arrival of the
heat equator
causes
convectional uplift over the continent and
hence low pressure. This draws warm moist air from
relatively higher pressure
maritime areas bringing
high levels of rainfall and humidity.
-
winter
monsoon: reverse of the summer system. The heat equator is
now over the maritime area and draws cool, dry air from
the continental mass which means cool, dry winter months
for the monsoon region.
Mor – a
humus layer with high
levels of acidity. Dark, even black in colour, not fully
decomposed and lacking in nutrients.
Moraine – debris deposited by a
glacier. Three main types:
-
terminal moraine – marks the furthest point the glacier
reached as it ‘bulldozed’ material ahead of the ice mass.
-
lateral moraine – deposits of load carried at the edges of
the glacier.
-
medial
moraine – deposits of the load carried in the middle of
the glacier where two lateral moraines came together from
tributary glacier.
Morphology – lit. form, shape
or structure. Can be applied in physical geography e.g. the
morphology of a hill, or human geography e.g. the morphology
of a village.
Mouth – where a river meets a body
of water.
Mudflow – a fairly rapid
mass
movement usually occurring after heavy rainfall.
Mull – a dark, crumbly, nutrient rich
humus layer.
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