Learn: Natural processes | Quizlet

Folding

the bending or curving of flat rock layers (strata) into wave-like structures due to intense compressional pressure inside the Earth. Folding is caused when 2 plates push against each other and the SOFTER rock is pushed and squeezed by the HARDER rock as the plates move. The soft rock then bends and twists to form hills and valleys

Folding within the TVC

This occurred in the TVC as the Pacific Plate subducted below the Australian plate. The overlying continental plate (Australian plate) is subjected to pressures which caused the young rocks to fold to form the Kaimanawas

Faulting

the movement of parts of the earth's surface along areas of weakness known as fault lines. When this movement is sudden it is called an earthquake. During faulting, land moves in large solid blocks of hard, unbending rock. Faulting is the fracturing of the Earth's crust accompanied by the relative displacement (shifting) of rock masses along a plane of weakness

Denudation

the geological process of wearing away, breaking down, and lowering the Earth's surface through weathering, mass wasting, and erosion.glacial (ice)

b. aeolian (wind)

c. fluvial (rivers)

VOlcanism

the geological process where molten rock, gases, and other materials rise from deep inside a planet or moon and break through the surface

Subduction

Subduction is a geological process where one tectonic plate moves under another and sinks into the Earth's mantle at a convergent boundary.

Volcanism/subduction in the TVC

Subduction occurs along the Kermadec Trench where the heavier, oceanic Pacific plate is forced below the lighter, continental Australian plate at a rate of 8 cm a year. The plate boundary is 100 km from Mt Tongariro. Friction generates heat which melts the Pacific plate to form magma which collects in a chamber below the TVC.

Weathering

Process where rock is broken down and eroded by the weather

Erosion

Process where rock is worn away

How do glaciers erode

A glacier erodes the valley floor and sides by plucking and abrasion

Plucking

ice touching the sides and ground can thaw slightly and then refreeze around rocks sticking out. When the glacier moves forward, it plucks these rocks away

Abrasion

debris carried in the glacier can scrape material off the valley walls and floor

Glaciers in the TVC

A large scale glacier used to exist in the Mangatepopo valley on Mt Tongariro in the TVC until this melted after the last ice age 100,000 years ago.

Currently the only glaciers that exist in the TVC are located on Mt Ruapehu such as the Whangaehu and Whakapapa. These are very small in comparison to the one that existed on Mt Tongariro.

Describe the water cycle

Heating by sunlight is the source for all changes in the weather.

Heat evaporates water and changes it into water vapour

The sun heats the earth and the ocean and lakes and it causes the vapour to rise.

As it rises it cools and condenses and makes all the clouds that we see in the sky.

All the clouds have been formed because the land and sea were warm and the vapour goes up with the air. You know that water evaporates when you see those clouds up there.

Evaporation and condensation, followed by precipitation.

The rain and the hail and the sleet and the snow falling down on the land and the sea, fill the lakes and the ponds and the rivers that flow to the oceans continually.

The heat giving sun just repeats what it has done and the vapour goes up with the air and you know that water can circulate when you see those clouds up there.

Orographic rainfall

Orographic rainfall is precipitation that forms when moist air is forced to rise over high landforms like mountains

Orographic rainfall in the TVC

The prevailing, moist westerly wind picks up moisture as it blows across the Tasman Sea and then towards the central North Island

This warm, moist air is forced to rise over the mountain barrier, as it rises, it cools, condenses and forms clouds to the west of Ruapehu.

This leads to increased amounts of rainfall on the west, while the east side of Ruapehu sits in the rainshadow area receiving less rainfall

As all the moisture leaves the air on the west side, the east side of Ruapehu receives a warm, dry wind which results in Rangipo Desert.

Describe adiabatic lapse rate

the rate at which a rising or sinking parcel of air changes its temperature due to expansion or compression, without exchanging heat with the surrounding environment. As air rises, pressure drops and the parcel expands and cools; as it sinks, it compresses and warms.

Adiabatic lapse rate of TVC

6.5°C per kilometer

Name the five groups of people influencing/being influenced by the TVC

Farmers

Tourists

Council

HEP operators

(Hydro electricity power operators)

Iwi

DOC

What have farmers done to the TVC?

Introduced new plants (grasses) and animals (sheep). Upset vegetation succession. Animals ate native plants. Shelter belts changed microclimate. Added fertilisers to aid soils, which changed natural conditions.

Tourists

In past, introduced plants like Heather, which caused erosion, as it does not bind soil layers together and spreads quickly. Others like rabbits became pests as it has no natural predators. Large no. of tourists caused erosion by walking on fragile environment

Council

Built roads and tourist centres that changed relief and altered drainage patterns.

HEP operators

(Hydro electricity power operators)

Altered the whole drainage pattern by rerouting rivers eg Whanganui and Whakapapa so diverted via canals into Lake Rotoaira and then tunnel to Tokaanu Power Station. This reduced flow of some rivers, affected wildlife like blue duck and increased sediment in lakes. Upset fluvial processes.

Iwi

Area is sacred to Maori especially Tuwharetoa due to legends etc. so anxious it does not get changed. Gifting in early days means that disruption was minimised.

DOC

The creation of ski lodges and ski fields on Ruapehu leads to pollution and scarring of landscape.

Whakapapa and Turoa ski fields modify the shape of the landscape to their own needs.