开放海域.ppt

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,THE OPEN OCEAN,Grade 3 Unit 2 Lesson 1,The ocean is the worlds largest habitat.,It covers about 70%of the Earths surface.,The ocean floor is not flat;it has valleys(canyons)and mountains(seamounts)just like those on land.,The ocean floor is not flat;it has valleys(canyons)and mountains(seamounts)just like those on land.,Use 3-D red/blue glasses to view this image.,Scientists divide the ocean into two zones:,benthic zone,pelagic zone,There are zones within the pelagic zone.,Lets learn them!,-,-,-,Photic Zone,Photic Zone,is the top layer,nearest the surface of the ocean and is also called the sunlight layer.In this zone enough light penetrates the water to allow photosynthesis.,photic zone,Disphotic Zone,The,Disphotic Zone,is found just below the Photic Zone and is known as the twilight layer.In this zone only a small amount of light penetrates the water.Plants do not grow here due to the insufficient amount of light.,photic zone,disphotic zone,Aphotic Zone,The darkness layer or,Aphotic Zone,is entirely dark meaning there is no light.About 90%of the ocean is in this layer.,The whale shark,like most marine organisms,is typically found in the,sunlight layer,or,photic zone,of the open ocean layers.,Animals that live in the,disphotic zone,like many types of squid,are adapted to life in near darkness,cold water,and high pressure.,Animals that thrive in the,aphotic zone,are used to living without light!,Name That Open Ocean Zone!,Photic zone,(sunlight zone),Name That Open Ocean Zone!,Photic zone,(sunlight zone),Disphotic zone,(twilight layer),Name That Open Ocean Zone!,Aphotic zone,(darkness layer),Name That Open Ocean Zone!,Photic zone,(sunlight zone),Disphotic zone,(twilight layer),Name That Open Ocean Zone!,Nice work!,Aphotic zone,Photic zone,Disphotic zone,The,End,