Download Grade 8 Science

Grade 8 Science
Chapter 2 Vocabulary
Unit 1
Salinity – The amount of salt dissolved in a specific amount of water.
Drainage System – the area of land from which water drains into a certain body of water.
Volcanic action – when heat and dust is coming from volcano
Erosion - weathering away of rocks
Plate Tectonics – huge rock plates that slip and slide under the earth’s crust and on top of the
mantle.
Glaciation – freezing of fresh water into large slabs of ice that usually does not thaw easily.
Continental margin – the continental shelf and slope together.
Continiental shelf – made from erosion of run off, located off the shore of land before the ocean
basin.
Continental Slope – where the continental shelf plummets downward to the ocean basin.
Abyssal Plain – The wide open regions of the ocean floor between the continents and the
mountain ranges at the centre of the ocean.
Mid ocean ridge – mountain range made by volcanic magma coming up through the ocean basin
because two tectonic plates opened up.
Sonar – used to measure depth of ocean – echo location.Sound wave goes down and comes back
to the ship.If it takes a short time for wave to come back – shallow water.Visa versa
Depth probe – piece of equipment used to measure depth of the ocean.
Coriolis Effect – The change in the direction of winds and currents caused by the rotation of
earth.
Satellite image – image received by satellite using radar,infrared light or other technologies.
Core Sampling – taking a large crosssection on land or ice from the earth to investigate it.
Submersible– strong machine vehicles that go into the water at great depths
Ocean currents – rivers of wtaer that run through the ocean
Labrador Current – cold water current from labrador that goers down by NL and then to the
Grank Banks
Gulf Stream Current – warm water current comes by NL from the Gulf.Goes to the Grand Banks
Surface Currents – currents on surface of water controlled by wind,coriolis effect and the size of
the continents.
Coriolis effect – for surface currents, currents go clockwise in northern hemiphere and counter
clockwise in southern hemisphere.
Deep Currents – currents that run deep in the ocean controlled by salinity and the ocean’s water
temperature.
Wave – the action of wind on the water
Wave Length – Distance from one wave crest to the next; length of one unit of a wave that
repeats itself.
Wave Height – Distance from wave crest to wave trough.
Crest – top of a wave
Swell – offshore wave with a trough,crest, and trough.
Breaker – inshore wave with just a trough and crest – gets higher in height as it comes into shore.
Trough – Lowest part of a wave.
Tsunami – A giant wave caused by an earth quake volcanic eruption or landslide on the ocean
floor.
Tide – slow rise and fall of the ocean based on the position of the sun,moon and earth.
Tidal range – difference in high tide and low tide
Spring Tide – The largest tidal range that occur when Earth, the Moon, and the Sun are in a line.
Neap Tides – smallest tidal range when sun,moon and earth are at right angles.
Bays – Indented areas of coastland or areas in the coastline that are in between headlands.
Shoreline – formation of land which makes up the headlands and the beaches.
Wave energy – circular movement of force going through the water
Headlands – shoreline rock marking the beginning and end of a bay made of igneous rock.
Bays – areas of land that in between headlands usually called beaches
Beach – area where you will find sand or small rocks between two headlands
Sand Bar – area of high land in the ocean caused by deposits in the form of sand
Sea Cave – erosion of sedimentary rock caused by waves action making a large indentation
Sea Arch – when a sea cave has completely been eroded through
Sea Stack – when the top of a sea arch falls into the ocean- what is left.
Breakwater – structure built to prevent erosion on shorelines
Jetty – wood structure to prevent erosion on either side of a waterered area
Wharf – wooden structure built to dock boats so boats will not be grounded and can stay in deep
water