How the ocean formed

Earth's ocean formed

• a million years ago

• a billion years ago

• 4 billion years ago

• last week

The ocean formed when

• water rose up from Earth's core

• water was released by early life on Earth

• steam from volcanos and accretion condensed and fell as rain

• all of these

The ocean is salty because

• ocean water evaporates

• rocks on Earth's surface weather and erode

• rivers carry minerals to the ocean and deposit them

• all of these

The reason why oceans are where they are is because

• they are on top of oceanic crust which is "lower" than continental crust

• they are on top of continental crust which is "lower" than oceanic crust

• they are below oceanic crust which is "lower" than continental crust

• they are below oceanic crust which is "higher" than continental crust

This layer of Earth is the thickest part

• crust
• outer core
• mantle
• inner core

The mantle of Earth is made partly of magma. When magma rises and sinks, this is called ______________. 

• a conduction current
• a hot spot
• a volcanic eruption
• a convection current

Tags

NGSS.MS-ESS2-1

Earth's tectonic plates are made of

• lithosphere and a wee bit of aesthenosphere

• crust only

• mantle only

• continents

Which is true about hotter material in the mantle?

• more dense, sinks
• less dense, sinks
• less dense, rises
• more dense, rises

Tags

NGSS.MS-ESS2-1

Plate movement is caused by _____

• The rotation of the Earth
• Ocean tides
• Convection current in the mantle
• The moon's gravity

Tags

NGSS.MS-ESS2-2

NGSS.MS-ESS2-3

Oceanic crust is

• Younger and less dense than continental crust
• Thinner, younger and more dense than continental crust
• Older, thicker and less dense that continental crust
• Bigger and younger than continental crust

Tags

NGSS.HS-ESS1-5

NGSS.HS-ESS2-1