WEBVTT 00:00:02.540 --> 00:00:03.500 [INTRO MUSIC] 00:00:10.020 --> 00:00:13.520 Look outside your window for a sec, and you'll probably see some buildings and streets, 00:00:13.520 --> 00:00:16.520 maybe telephone poles, hopefully some trees in there too. 00:00:16.520 --> 00:00:20.440 A lot of the world that we live in has been shaped by people, and hey, no complaints, because 00:00:20.440 --> 00:00:21.790 I'm plenty comfortable right here. 00:00:21.790 --> 00:00:25.220 But people aren't the only ones moving things around and shaping our world. 00:00:25.220 --> 00:00:30.219 Wind, rain, and other elements do it all the time, making shapes out of the Earth we call landforms. 00:00:30.220 --> 00:00:33.280 So what are some kinds of landforms, and how are they made? 00:00:37.620 --> 00:00:40.280 First, remember that the Earth is made of several spheres, 00:00:40.280 --> 00:00:43.840 including the hydrosphere, biosphere, atmosphere and geosphere. 00:00:43.840 --> 00:00:49.280 The solid part of the Earth, or geosphere, may look pretty stable, but it's always changing. 00:00:49.280 --> 00:00:53.340 Weathering and erosion by wind and water are constantly reshaping what our planet's surface 00:00:53.340 --> 00:00:57.380 looks like, and even if it takes so long that we don't usually notice it, it's happening. 00:00:57.380 --> 00:01:01.020 Let's check out our map to explore what kinds of landforms there are around the world. 00:01:05.060 --> 00:01:08.080 Mountains are probably some of the most well known landforms. 00:01:08.080 --> 00:01:13.240 Basically, they're just really big hills with steep sides that stretch way above the surface of the Earth. 00:01:13.240 --> 00:01:18.660 Many mountains are formed when large plates, or pieces of the Earth's surface, collide and are forced upwards. 00:01:18.660 --> 00:01:21.400 The low spaces in between? We call those valleys. 00:01:21.400 --> 00:01:25.100 But if mountains don't 'peak' your interest, how about plateaus? 00:01:25.100 --> 00:01:30.260 Plateaus are also tall landforms, but unlike mountains, which tend to have the pointy tops we know as peaks, 00:01:30.260 --> 00:01:31.620 plateaus have flat tops. 00:01:31.620 --> 00:01:33.480 Plateaus come in lots of sizes. 00:01:33.480 --> 00:01:37.940 If they're medium-sized, for example, they're called mesas, which is the Spanish word for table, 00:01:37.940 --> 00:01:41.860 which is highly appropriate, since plateaus kind of look flat and long -- like tables. 00:01:41.860 --> 00:01:44.220 And if they're smallish, they're called buttes. 00:01:44.220 --> 00:01:48.200 No matter what they're called, or what size they are, plateaus can form in lots of different ways. 00:01:48.200 --> 00:01:51.620 Sometimes they're caused by the erosion, or wearing away of mountains, 00:01:51.620 --> 00:01:53.880 like by water or really big pieces of ice. 00:01:53.880 --> 00:01:58.400 Other plateaus are made by magma, which is really hot melted liquid Earth below the surface. 00:01:58.400 --> 00:02:01.240 When magma swells up below the surface but can't break through, 00:02:01.240 --> 00:02:05.100 it can push up a flat chunk of land, leaving that table like formation behind. 00:02:05.100 --> 00:02:07.300 And speaking of magma, let's go to the Pacific Ocean on our map 00:02:07.300 --> 00:02:09.480 for a good look at the most explosive landforms: 00:02:09.860 --> 00:02:10.700 Volcanoes. 00:02:10.700 --> 00:02:13.480 These landforms are found where the surface of the Earth is relatively thin. 00:02:13.480 --> 00:02:18.280 When magma breaks through the surface, or erupts, that hot liquid rock gets a new name: 00:02:18.540 --> 00:02:19.320 Lava. 00:02:19.320 --> 00:02:21.120 And a new volcano is born. 00:02:21.120 --> 00:02:22.540 Hot stuff coming through! 00:02:22.540 --> 00:02:26.020 'Hot' is definitely a good term to describe another kind of land form: 00:02:26.310 --> 00:02:27.030 Deserts. 00:02:27.030 --> 00:02:31.740 Deserts are landforms that lose more water to air than they get through rain, snow, or other kinds of moisture. 00:02:31.740 --> 00:02:34.600 The world's largest desert is the Sahara in Northern Africa, 00:02:34.600 --> 00:02:38.780 where daytime temperatures can climb to a sweltering 55°C! 00:02:38.780 --> 00:02:43.540 Just a wee bit out of my personal comfort zone, but then again so are the cold temperatures in Antarctica, 00:02:43.540 --> 00:02:45.600 which is actually considered to be a desert too. 00:02:45.600 --> 00:02:47.900 Penguins in the desert! Who knew it, right? 00:02:47.900 --> 00:02:50.660 Time to set sail for two more kinds of landforms: 00:02:50.660 --> 00:02:52.060 Islands and Deltas. 00:02:52.060 --> 00:02:55.540 You'll find deltas at the mouth, or end, of rivers where they meet the ocean. 00:02:55.540 --> 00:02:58.880 Deltas are formed when dirt and other debris that are washed down the river accumulate, 00:02:58.880 --> 00:03:01.020 or build up, to form a piece of land. 00:03:01.020 --> 00:03:03.880 Islands, on the other hand, can form any number of ways. 00:03:03.880 --> 00:03:06.560 They might come from the cooled lava of underwater volcanoes, 00:03:06.560 --> 00:03:10.880 or from a whole lot of dirt sand in pieces of coral building up due to ocean currents. 00:03:10.880 --> 00:03:13.880 Islands can even form by breaking off from a larger piece of land! 00:03:13.880 --> 00:03:18.960 So they can form in lots of ways, but as long as it's surrounded on all sides by water, it's an island. 00:03:22.920 --> 00:03:26.260 In our travels today, we took a look at lots of different kinds of landforms, 00:03:26.260 --> 00:03:28.620 which are natural features of the Earth's surface. 00:03:28.620 --> 00:03:32.920 Landforms can stretch high above the Earth's surface, like mountains, plateaus, or mesas, 00:03:32.920 --> 00:03:37.480 be created in or by water like deltas and islands, or even be dry like deserts. 00:03:37.480 --> 00:03:39.980 So remember these things the next time you step outside. 00:03:39.980 --> 00:03:43.620 Underneath and beyond and all around the things that people have made, 00:03:43.620 --> 00:03:46.820 there are landforms millions of years in the making. 00:03:46.820 --> 00:03:48.860 [OUTRO MUSIC]