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Question	Answer
State a characteristic of a river dominated Delta	an elongated build up sediment moving off shore
The net force acting on a fluid is called the...	Tide Generating Force
What are the 2 delta sub-environments?	1) Delta Plain - river dominant 2) Delta Front - interacts with marine and fluvial outflow
where is the sediment of no deltaic shorelines derived from?	Longshore transport, onshore transport from shoreface and from sea level rise and fall.
hows long is a lunar day?	24 hours and 50 minutes
State the 3 main processes which can erode, transport and deposit sediments.	1) Pelagic Settling 2) Semi Permanent bottom currents 3) Slides, debris flows etc.
9) What is Denudation?	9) Involves the removal of weathered material from the site of weathering – begins transporting
State 3 facts abpout pelagic settling	1) sediment is generated in the open sea. 2)Mostly Biogenic (>75%) 3) Has some non-biogenic components
State 2 facts about hemipelagic settling	1) Land derived (terrigenous) Sediment 2)siliciclatic Clay and silt
10) What are the functions of weathering	10) Reduces rock strength and increases permeability Produces minor landforms and micro-relief in soluable rocks The first step of soil formation
what is Pelagic Rain?	an open ocean site of constant fallout of biogenic sediment
What is a Lysocline?	an area where rates of dissolution of CaCO3 increase rapidly
11) what is Ice Wedging?	11) water penetrates the cracks in rocks and when it freezes, it expands increasing the size of the crack
why does Oxygen 16 water have weaker bonds than oxygen 18 water?	Oxygen 16 is lighter. Lighter molecules have a higher vibration energy
Newtons Universal Law of Gravitation	F=γ (m1 X m2)/r^2 Y = Universal Gravitational constant. 6.67X10-11 m1 = Mass of a body 1 m2 = mass of a body 2 r = distance between centres of mass
what is salt weathering?	The expansion of minerals by heating or hydration causes the rock to break. (same as ice wedging)
Dissolution is where ....	Water breaks down ionic bonds in minerals, the minerals are then leached away with the water
Outline what a graded stream profile is:	A profile of a stream measuring the velocity, load gradient and volume of water
What are river systems characterised by?	1)Unidirectional Flows 2)Sediment transport as bed, bed - contact and suspended load
Outline the first sub environment of a river system: Channels	1) Confined Flows 2) Variable depth, width and discharge 3) contains current generated badforms
Outline the second sub environment: overbank environments	1) unconfined flows e.g. floodplains 2) overbank facies e.g. single flood event
The Earth's Orbit around the Sun is not constant and can explain short term climate change? T Or F?	True
What is Eccentricity?	Refers to the shape of the Earths Orbit around the sun
What is Obliquity?	Refers to the tilt of the Earths Axis
What is Axial Precession?	Refers to the wobble of the axis of rotation Causes seasonal change
State the properties of Oxygen 16 in water:	1) Makes up 99.8% of water 2)evaporates easier 3)precipitates less easily
What is the reason for changes in the Earths Orbit?	Gravitational forces cause by other planets in the solar system
The moon exerts twice the gravitational attraction and tide generating force than the sun.... why?	Because it is closer to the Earth
What is the effect of changes in the Earths Orbit?	The amount and distribution of solar radiation oscillates with time
State the properties of Oxygen 18 in water:	1)0.2% of water 2)11% heavier 3)Evaporates less easily 4)Precipitates more easily
What is the periodicity of Eccentricity?	100,000 years +/- 400,000
What is the periodicity of Obliquity?	41,000 years
When do spring tides occur?	When the Earth, Moon and Sun are all aligned coincide with full and new moons
What is the periodicity of Axial Procession?	23,000 years +/- 19,000 years.
When do Neap tides occur?	When the Earth, Moon and Sun are aligned at a right angle
what are the 3 types of tide?	Diurnal, semidiurnal and mixed
outline the ice forming config and its net effect: ICE AGE	Very rounded orbit Low Axial tilt Large Earth-Sun distance in Summer Net Effect = Small seasonal contrast, Permas frost doesnt melt and increases the following winter
Outline the Ice Melting Config and its net effects: NOW	Very Elliptical Orbit High Axial Tilt Small Earth-Sun distance in summer Net Effect= Large seasonal contrast, Perma frost melts and reforms the following winter
Flow Velocity	∪=C√RS U= Mean flow in M/s C= Chezy Coeffiecient R= Hydraulic Radius S= X-Section area
1) What are the main methods of sediment Transport?	1) Gravity - creeping, slumping, rock flow 2) Fluids (flowing as currents) 3) Ice (glacial)
what did the uplift of the Tibetan Plateu cause?	Blockage of mid-latitude air flow causing the Northern Hemisphere to cool
What is Sinuosity?	Channel length/ Valley length
2) what is creep and how fast does it move per year?	2) i)The Downslope movement of regolith resulting in the rearrangment of particles. ii) 1-2mm per year
3) what is solification?	2) seasonal slippage of melt water and upper layers of regolith
4) What are debris flows?	4) suspension of sedimentary grains in a mud-water matrix.
A braided river	Is broken up by bars of sediment
The Delta Nomination working out Oxygen Isotope ratios -	Image: Picture1 (image/png)
5) What is Laminar flow	5) Particles flow in straight lines
We can measure past climates using oxygen isotopes by....	Using the shells of microfossils called Foraminifera which secrete CaCO3. The oxygen in the CaCO3 comes from the seawater at that time
6) What is Turbulent Flow?	6) particles move all over the place!
7) How do particles with low viscosities flow?	7) turbulently
State the 2 different types of Foraminifera	1) Bentic - Deep water in ocean oceans 2) Planktonic - live in shallow water of the open oceans
Reynolds Number	Re=Ul/v U= velocity of flow l = Turbulent flow Depth v = kinematic viscosity of fluid
What is a delta?	A wedge of sediment formed at a river mouth
Delta Classification	Image: F1_large (image/jpg)
Deep water motion is driven by density differences between water masses, due to....	Temperature differences Salinity differences Thermohaline circulation!
State a characteristic of a Wave dominated delta	Flat delta profile
Outline the global conveyor belt	1) Water from the pacific and indian oceans cools and sinks in the North Atlantic. 2) flows back to the indian and pacific oceans 3) Upwelling forces deep water to rise and warm where it flows back to the North Atlantic.
State a characteristic of a Tide dominated delta	Abundant funnel shaped channels. They accommodate tidal exchange

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	Created by Gavin Niall about 11 years ago