1 00:00:02,290 --> 00:00:14,019 Look outside your window for a sec and you'll probably see some buildings and streets, maybe 2 00:00:14,019 --> 00:00:16,519 telephone poles, hopefully some trees in there too. 3 00:00:16,519 --> 00:00:20,420 A lot of the world that we live in has been shaped by people, and hey, no complaints because 4 00:00:20,420 --> 00:00:22,019 I'm plenty comfortable right here. 5 00:00:22,019 --> 00:00:25,320 But people aren't the only ones moving things around and shaping our world. 6 00:00:25,320 --> 00:00:29,579 Wind, rain, and other elements do it all the time, making shapes out of the earth we call 7 00:00:29,579 --> 00:00:30,579 landforms. 8 00:00:30,579 --> 00:00:37,950 So what are some kinds of landforms, and how are they made? 9 00:00:37,950 --> 00:00:42,409 Just remember that the Earth is made of several spheres, including the hydrosphere, biosphere, 10 00:00:42,409 --> 00:00:44,009 atmosphere, and geosphere. 11 00:00:44,009 --> 00:00:49,490 The solid part of the Earth, or geosphere, may look pretty stable, but it's always changing. 12 00:00:49,490 --> 00:00:53,289 Weathering and erosion by wind and water are constantly reshaping what our planet's surface 13 00:00:53,289 --> 00:00:57,409 looks like, and even if it takes so long that we don't usually notice it, it's happening. 14 00:00:57,409 --> 00:01:05,579 Let's check out our map to explore what kinds of landforms there are around the world. 15 00:01:05,579 --> 00:01:08,180 Mountains are probably some of the most well-known landforms. 16 00:01:08,180 --> 00:01:13,439 Basically, they're just really big hills, with steep sides that stretch way above the surface of the Earth. 17 00:01:13,439 --> 00:01:18,859 Many mountains are formed when large plates, or pieces of the Earth's surface, collide and are forced upwards. 18 00:01:18,859 --> 00:01:21,439 The low spaces in between, we call those valleys. 19 00:01:21,439 --> 00:01:25,359 But if mountains don't peak your interest, how about plateaus? 20 00:01:25,359 --> 00:01:31,739 Plateaus are also tall landforms, but unlike mountains, which tend to have the pointy tops we know as peaks, plateaus have flat tops. 21 00:01:31,739 --> 00:01:33,620 Plateaus come in lots of sizes. 22 00:01:33,620 --> 00:01:37,959 If they're medium-sized, for example, they're called mesas, which is the Spanish word for table, 23 00:01:37,959 --> 00:01:41,799 which is highly appropriate since plateaus kind of look flat and long, like tables. 24 00:01:41,980 --> 00:01:44,060 And if they're smallish, they're called buttes. 25 00:01:44,200 --> 00:01:48,099 No matter what they're called or what size they are, plateaus can form in lots of different ways. 26 00:01:48,400 --> 00:01:51,379 Sometimes they're caused by the erosion or wearing away of mountains, 27 00:01:51,599 --> 00:01:53,879 like by water or really big pieces of ice. 28 00:01:54,000 --> 00:01:58,180 Other plateaus are made by magma, which is really hot, melted liquid earth below the surface. 29 00:01:58,500 --> 00:02:01,140 When magma swells up below the surface but can't break through, 30 00:02:01,140 --> 00:02:04,900 it can push up a flat chunk of land, leaving that table-like formation behind. 31 00:02:05,019 --> 00:02:07,280 And speaking of magma, let's go to the Pacific Ocean on our map 32 00:02:07,280 --> 00:02:10,439 for a good look at the most explosive landforms, volcanoes. 33 00:02:10,699 --> 00:02:13,560 These landforms are found where the surface of the Earth is relatively thin. 34 00:02:13,879 --> 00:02:16,159 When magma breaks through the surface or erupts, 35 00:02:16,379 --> 00:02:19,159 that hot liquid rock gets a new name, lava, 36 00:02:19,400 --> 00:02:22,419 and a new volcano is born, hot stuff coming through. 37 00:02:22,580 --> 00:02:27,039 Hot is definitely a good term to describe another kind of landform, deserts. 38 00:02:27,319 --> 00:02:29,280 Deserts are landforms that lose more water to air 39 00:02:29,280 --> 00:02:31,659 than they get through rain, snow, or other kinds of moisture. 40 00:02:31,860 --> 00:02:34,539 The world's largest desert is the Sahara in northern Africa, 41 00:02:34,539 --> 00:02:38,439 where daytime temperatures can climb to a sweltering 55 degrees Celsius. 42 00:02:38,919 --> 00:02:41,039 Just a wee bit out of my personal comfort zone. 43 00:02:41,340 --> 00:02:43,439 But then again, so are the cold temperatures in Antarctica, 44 00:02:43,680 --> 00:02:45,580 which is actually considered to be a desert too. 45 00:02:45,740 --> 00:02:47,800 Penguins in the desert. Who knew it, right? 46 00:02:47,960 --> 00:02:51,919 Time to set sail for two more kinds of landforms, islands and deltas. 47 00:02:52,139 --> 00:02:55,280 You'll find deltas at the mouth or end of rivers where they meet the ocean. 48 00:02:55,780 --> 00:02:58,919 Deltas are formed when dirt and other debris that are washed down the river accumulate 49 00:02:58,919 --> 00:03:00,919 or build up to form a piece of land. 50 00:03:01,099 --> 00:03:03,719 Islands, on the other hand, can form any number of ways. 51 00:03:03,719 --> 00:03:08,379 They might come from the cooled lava of underwater volcanoes, or from a whole lot of dirt, sand, 52 00:03:08,460 --> 00:03:10,860 and pieces of coral building up due to ocean currents. 53 00:03:10,979 --> 00:03:14,699 Islands can even form by breaking off from a larger piece of land, so they can form in 54 00:03:14,699 --> 00:03:18,759 lots of ways, but as long as it's surrounded on all sides by water, it's an island. 55 00:03:22,629 --> 00:03:26,629 In our travels today, we took a look at lots of different kinds of landforms, which are 56 00:03:26,629 --> 00:03:28,349 natural features of the Earth's surface. 57 00:03:28,750 --> 00:03:32,629 Landforms can stretch high above the Earth's surface, like mountains, plateaus, or mesas, 58 00:03:32,629 --> 00:03:37,650 Be created in or by water, like deltas and islands, or even be dry, like deserts. 59 00:03:37,650 --> 00:03:40,129 So remember these things the next time you step outside. 60 00:03:40,129 --> 00:03:45,129 Underneath and beyond and all around the things that people have made, there are landforms, 61 00:03:45,129 --> 00:03:47,930 millions of years in the making.