Permafrost

Some ___ million square miles of permafrost — ___ percent of the world’s total — could disappear by the end of the century.

• 2.5/40

• 1/25

• 3.5/50

• 0.5/10

Tags

NGSS.HS-ESS2-2

NGSS.HS-ESS2-6

NGSS.HS-ESS3-5

An estimated _____ gigatons of carbon are frozen in Arctic permafrost, making it one of the world’s largest carbon sinks.

• 1,400

• 1,500

• 1,000

• 100

Tags

NGSS.HS-ESS2-6

The soil above the permafrost or bedrock,

called the ______ layer, becomes saturated like a wet

sponge.

Which of the following surface features most likely contribute to the early formation of a tundra lake?

• pingo

• thermokarst

• talik

• ice wedges

Tags

NGSS.MS-ESS2-2

NGSS.MS-ESS2-4

What best explains the expansion and contraction of tundra soil which tends to move surface stones laterally across the ground. The movements create sorted nets, circles, and polygons rimmed by large- and medium-sized stones with centers of fine silt or clay material.

• Freeze and thaw

• Gravity cycles

• Pingo formation

• Density variation

Answer explanation

In soils containing rocks, the forces created by

seasonal freezing and thawing move – and sometimes sort – soil particles. Although the exact processes that cause this are still debated, scientists agree that different rates of freezing and the forces of expansion, contraction, and gravity are involved.

Tags

NGSS.MS-ESS2-2

Why is permafrost thawing?

• Global warming

• Fishing

• Change of seasons

Tags

NGSS.MS-ESS3-5

Match soil characteristics of the Tundra:

• thawed top layer, acidic from decomposing pine needles

• fresh top layer, nutrient rich from snow melt

• permafrost in winter, complete thaw for summer, nutrient rich

• permafrost year round, even under summer soil, nutrient poor

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-4

_______________ is a permanently frozen layer of soil beneath the surface of the ground.

• eutrophication

• permafrost

• aquifer

• urbanization

Ground that is always frozen is called:

• freezy ground

• permafrost

• the deep freeze

• hot lands

What is permafrost?

• A permanently frozen layer of soil

• A type of volcanic rock

• A seasonal ice formation

• A type of desert soil

Tags

NGSS.MS-ESS2-4