part one

Question 1

uniformitarianism

Answer 1

the idea that geomorphic processes are a result of laws that are uniform through time and space therefore we can look into past to understand landscape evolution and interpret earth history

Question 2

when was uniformitarianism first proposed and by who

Answer 2

in 18th cent in response to catastrophism by hutton and popularised by lyell

Question 3

what has the inital uniformitatrian

Answer 3

the uniformity of processes rates and states and landscapes (no dynamic variability, unpredicitatedn events and catastrophies)

Question 4

what are the two types of uniformintarnisms

Answer 4

1. metholodical (different rates of chnage and non linear events however uniform laws - by GOULD 1965)
2. substantive (lyell and hutton steady rates overtime)

Question 5

describe geomorphic systems thinking

Answer 5

a system is limited by a boundary comprising of internal components and processes that create outputs and inputs of enegery

Question 6

why do we see the same landscapes and patterns repeatted

Answer 6

equilibium theory. balance of competing forces. a normal state for a geomorphic system

Question 7

what is base level

Answer 7

the lowest altitude at which erosion can occur (sea level or local base eg dam)

Question 8

rejuvination

Answer 8

regarding of river profile in reponse to change in base level

Question 9

what is dynamic equilivium

Answer 9

constant rebalancing in reponse to exogenous forces

Question 10

what is meta stable equilibrium

Answer 10

more than one equilibium state defined by thresholds and history

Question 11

what is the cyclical model of earth surface

Answer 11

by william davis

planation and denudation. all systems wear down

Question 12

what us denudation

Answer 12

wearing of earrths through erosion

Question 13

what is planation

Answer 13

denudation pathways to base level

Question 14

peneplain

Answer 14

large continuous low releif area to base level

Question 15

pediplanation

Answer 15

denundation through scarp retreat and slopes remain

Question 16

what is a critical zone

Answer 16

area of focus, air to ground water all processes reponsible for converting bedrock to soil

Question 17

how is the climate a major exogeneous control

Answer 17

temp and precipitation: control of weathering on system. (denudation rates)
shallow soils in dry cold regions vs deep soils in humid wet areas

Question 18

what are 3 characteristsic of the creatceous climate

Answer 18

high hates of co2, global mean temp 10 degrees more

strong hydrological cycles

high sea levels (no ice caps) ~200 m higher

Question 19

when was the createous

Answer 19

100 million years

Question 20

evidence of createous climate

Answer 20

stomata based fossils (less frequent and smaller stomata due to excess co2)

Question 21

how has the temperature gradient different fro createous vs now

Answer 21

createous was less extreme, mean average at poles14 degrees. today with ice at caps there is more of a gradient due to albedo effect

Question 22

what caused high co2

Answer 22

degassing of rock reservoir due to high tectonic activity, and super plumes. production exceeded rate of sequestration

Question 23

what caused high sea levels

Answer 23

Bathymetry: rapid production of new ocean crust pushed up water due to higher elevation (less dense),

lack of ice caps

thermal expansion

more hydological cycle

Question 24

what caused the progressive cooling

Answer 24

slowing of mantle convection reduced seafloor spreading, concumption of co2 by chemcial weathering (more sequestration), aging of oceanic crust and permanent ice albedo