Landforms Flashcards
what are the phases of the historical study of landforms?
Phase 1 - exploration of the world (to mid 19th century)
phase 2 - establishment of the discipline - early theories of environmentalism (late 19th century)
phase 3 - dominance of regonal geography (detailed area descriptions - early 20th century)
phase 4 - emergence of human and physical geog - mid 20th century)
phase 5 - physical, integrated and human geography (late 20th century)
what was physical geography before 1800?
- Ancient Greeks and Romans were concerned with topographic descriptions of places and maps
- Dark Age Europe merely relied on Greek and Roman texts and rejected anything against the teachings of the church
- Arab geographers were pioneering fieldwork
- Chinese triangulation techniques for mapping
The Renaissance 15th and 16th Centuries
- Renewed interest in geographical knowledge of the ancients due to issues of exploration, patriotism and colonization
- Period of major invention and discovery
- Time keeping, mapping and printing
- Importance began to be placed on real-world experience (triumph of experience over authority was central at that time)
what is catastrophism and when was it around as a theory?
until 1830s
Ascribes the origin of Earth’s landforms to one or more “catastrophic” themes:
- instantaneous formation during Creation
- formation after Noah’s Flood
- earthquake and volcanic activity
who was George Cuvier and what did he explain?
(1769-1832)
french anatomist and paleontologist, explained the patterns of extinction and faunal succession observed in the fossil record.
who translated cuvier’s work and linked it with the biblical flood?
Robert Jameson (1774-1854)
whats uniformitarianism and when was it around?
1830-1930+
also termed gradialism
‘the present is key to the past’ - coined by William Whewell in a review of Lyell’s book
natural processes shape landforms through gradual changes over long periods of time.
uniformitarianism does not include…
the role of catastrophic events. eg volcanic eruptions, meteorite impacts, massive floods.
Coming from the Romantic school of thought, WHO believed that “…nature is perfect till man deforms it with care”
Alexander von Humboldt (1769-1859)
Who extended uniformitarianism to biology (evoloution) and wrote the book ‘origin of species’ (1859) stating humans and animals were not that different at all?>
Charles Darwin (1809-1882)
who suggested the cycle of erosion?
William Morris Davies (1850-1934)
compatible with uniformitarianism
what is the davisian cycle of erosion?
1890-1950,
a) young uplifted stage with very limited incision
b) mature stage with deep valley incision and complex topography
c) old eroded landscape with few geographic features
stages = structure, process, time
what was the glacial theory?
1840 - louis agassiz
multiple glaciations
most of northern america, n europe, n asia had been covered in ice sheets later termed the pleistocene
who wrote ‘The Great Ice Age and its Relationship to the Antiquity of Man’
James Geike, 1874
who was Grove Karl Gilbert?
(1843-1918)
- American geologist who joined the famous ‘Powell Survey’ in Rocky Mountain Region in 1874
- Recognized importance of describing physical processes and systems of laws (using quantitative methods)
- Proposed concept of dynamic equilibrium
- Detailed analysis of fluvial processes in his work ‘Geology of the Henry Mountains’ (1877)
- Gilbert’s ideas did not become popular until 1950s
when was the quantitative revoloution?
1950s, a period of global moderntiy (science driving society) Arthur Strahler (1918-2002) argued the need for physically-based real-world measurements (opposed to Davis) Move towards quantitative and statistical approaches
what is the ‘Strahler Stream Order’
1952, a system developed for classifying streams according to the power of their tributaries
what is the ‘equilibrium concept’
Hack 1960 realised -
- Rather than a single long Davisian erosion process there is a more dynamic set of processes (non-cyclic)
- Rejuvenated Gilbert’s concepts of dynamic equilibrium
- often depends where and when you measure something as to whether it shows equilibrium
what are the 3 timescales of equilibrium?
(a) dynamic equilibrium, 10,000 years (cyclic time);
b) steady-state equilibrium, 100 years (Graded time);
(c) static equilibrium, 0.1 years (static time)
who proposed the climatic geomorphology?
Julius Büdel (1903-1983)
what are the 3 types of geomorphology?
- Historical geomorphology Catastrophism and Uniformitarianism - Process geomorphology Gilbert and Strahler - Climatic geomorphology Büdel
what sociologist tried to distinguish science from religion?
Auguste Comte (1820s)
response to large events depends on….
the time since the last event (relaxation time)
- a large flood event may carry less sediment because a first flood flushed it all out
- ecosystem disturbance causes species to decline - needs sufficient time to recover to original levels.
- environmental response to a particular event depends on the sensitivity of the particular environment.
historical overview - what hapenned in 1950s?
Quantitative revolution (positivist science)
historical overview - what hapenned in 1970s?
cause - effect relationships became the focus
historical overview - what hapenned in 1990s?
realism (importance of case studies) proposed alternative to the problems of positivism
