{"page":"\u003clink rel=\"stylesheet\" href=\"https://lessonplanet.com/assets/packs/css/resources-c03aa079.css\" /\u003e\n\u003clink rel=\"stylesheet\" href=\"https://lessonplanet.com/assets/packs/css/lp_boclips_stylesheets-517835be.css\" media=\"all\" /\u003e\n\u003cdiv data-title='Why Earth Has Two Levels' data-url='/boclips/videos/5f871ccff015e06667da41cf' data-video-url='/boclips/videos/5f871ccff015e06667da41cf' id='bo_player_modal'\u003e\n\u003cdiv class='boclips-resource-page modal-dialog panel-container'\u003e\n\u003cdiv class='react-notifications-root'\u003e\u003c/div\u003e\n\u003cdiv class='rp-header'\u003e\n\u003cdiv class='rp-type'\u003e\n\u003ci aria-hidden='true' class='fai fa-regular fa-circle-play'\u003e\u003c/i\u003e\nVideo\n\u003c/div\u003e\n\u003ch1 class='rp-title' id='video-title'\u003e\nWhy Earth Has Two Levels\n\u003c/h1\u003e\n\u003cdiv class='rp-actions'\u003e\n\u003cdiv class='mr-1'\u003e\n\u003ca class=\"btn btn-success\" data-posthog-event=\"Signup: LP Signup Activity\" data-posthog-location=\"body_link_boclips\" data-remote=\"true\" href=\"/subscription/new\"\u003e\u003cspan\u003e\u003cspan\u003eGet Free Access\u003c/span\u003e\u003cspan class=\"\"\u003e for 10 Days\u003c/span\u003e\u003cspan\u003e!\u003c/span\u003e\u003c/span\u003e\u003c/a\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv class='rp-body'\u003e\n\u003cdiv class='rp-info'\u003e\n\u003cdiv aria-label='Hide resource details' class='rp-hide-info' role='button' tabindex='0'\u003e\u0026times;\u003c/div\u003e\n\u003ci aria-label='Expand resource details' class='rp-expand-info fai fa-solid fa-up-right-and-down-left-from-center' role='button' tabindex='0'\u003e\u003c/i\u003e\n\u003ci aria-label='Compress resource details' class='rp-compress-info fai fa-solid fa-down-left-and-up-right-to-center' role='button' tabindex='0'\u003e\u003c/i\u003e\n\u003cdiv class='rp-rating'\u003e\n\u003cspan class='resource-pool'\u003e\n\u003cspan class='pool-label'\u003ePublisher:\u003c/span\u003e\n\u003cspan class='pool-name'\u003e\n\u003cspan class='text'\u003e\u003ca data-publisher-id=\"30358007\" href=\"/search?publisher_ids%5B%5D=30358007\"\u003eMinuteEarth\u003c/a\u003e\u003c/span\u003e\n\u003c/span\u003e\n\u003c/span\u003e\n\u003c/div\u003e\n\u003cdiv class='rp-description'\u003e\n\u003cspan class='short-description'\u003eEarth’s outer shell is made of two materials whose different densities and thicknesses give rise to two distinct “levels” on the planet’s surface.Watch our new show Paradigms (U.S. servers...\u003c/span\u003e\n\u003cspan class='full-description hide'\u003eEarth’s outer shell is made of two materials whose different densities and thicknesses give rise to two distinct “levels” on the planet’s surface.\u003cbr/\u003e\u003cbr/\u003eWatch our new show Paradigms (U.S. servers \u003ca href='https://www.vrv.co/paradigms' target='_blank' rel='nofollow'\u003eonly!)\u003c/a\u003e\u003cbr/\u003e\u003cbr/\u003e___________________________________________\u003cbr/\u003e\u003cbr/\u003eTo learn more, start your googling with these keywords: \u003cbr/\u003eHypsometric Curve: Basically, a chart that shows the proportions of surface area at every elevation on a planet. \u003cbr/\u003eCrust: Earth's outermost layer, made out of two distinct materials – oceanic crust (which is denser) and continental crust (which is less dense). \u003cbr/\u003eLithosphere: The rigid outer layer of Earth, including the crust and the hard, un-bending part of the upper mantle. \u003cbr/\u003eSubduction: The process of an ocean plate crashing into another plate and getting forced to dive down into Earth's mantle. \u003cbr/\u003eIsostasy: Describes the way earth's crust sort of floats in the underlying mantle. Continental crust is less dense and thicker, and floats higher than the oceanic crust, which is denser and thinner. Geologists talk about things like \"isostatic rebound,\" which is what happens after an ice age, when the ice melts off a continent and the continent lifts up, like a floating raft in a pool after someone gets off (though continents rise more slowly). \u003cbr/\u003e___________________________________________\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eCredits (and Twitter handles):\u003cbr/\u003eScript Writer: Emily Elert (@eelert)\u003cbr/\u003eScript Editor: Alex Reich (@alexhreich)\u003cbr/\u003eVideo Illustrator: Ever Salazar (@eversalazar)\u003cbr/\u003eVideo Director: Emily Elert (@eelert)\u003cbr/\u003eVideo Narrator: Emily Elert (@eelert)\u003cbr/\u003eWith Contributions From: Henry Reich, Kate Yoshida, Peter Reich, David Goldenberg \u003cbr/\u003eMusic by: Nathaniel \u003ca href='http://www.soundcloud.com/drschroeder' target='_blank' rel='nofollow'\u003eSchroeder\u003c/a\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e___________________________________________\u003cbr/\u003e\u003cbr/\u003eReferences:\u003cbr/\u003e\u003cbr/\u003eAlbarede, F. (2009) Volatile accretion history of the terrestrial planets and dynamic implications. Nature, Vol 461.\u003cbr/\u003e\u003cbr/\u003eCalogero, Meredith. Personal Communication, 2018. \u003cbr/\u003e\u003cbr/\u003eEakins, B.W. and G.F. Sharman. Hypsographic Curve of Earth's Surface from ETOPO1, NOAA National Geophysical Data Center, Boulder, CO, 2012\u003cbr/\u003e\u003ca href='https://www.ngdc.noaa.gov/mgg/global/etopo1_surface_histogram.html' target='_blank' rel='nofollow'\u003efrom\u003c/a\u003e\u003cbr/\u003e\u003cbr/\u003eHawkesworth, C. J. \u0026 Kemp, A. I. S. (2006) Evolution of the continental crust. Nature, Vol 443.\u003cbr/\u003e\u003cbr/\u003eRosenblatt, P.C , \u0026 Thouvenot, P.E. (1994). Comparative hypsometric analysis of Earth and Venus. Geophysics Research Letters, Vol 21, pp 465-468.\u003cbr/\u003e\u003cbr/\u003eStern, R.J., Gerya, T, \u0026 Tackley, P.J. (2018) Stagnant lid tectonics: Perspectives from silicate planets, dwarf planets, large moons, and large asteroids. Geoscience Frontiers, 9.\u003c/span\u003e\n\u003c/div\u003e\n\u003cdiv class='action-container flex justify-between'\u003e\n\u003cbutton aria-expanded='false' aria-label='Read more description' class='rp-full-description' type='button'\u003e\n\u003ci class='fai fa-solid fa-align-left'\u003e\u003c/i\u003e\n\u003cspan id='read_more'\u003eRead More\u003c/span\u003e\n\u003c/button\u003e\n\u003cdiv class='rp-report'\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv aria-labelledby='resource-details-heading' class='rp-info-section'\u003e\n\u003ch2 class='title' id='resource-details-heading'\u003eResource Details\u003c/h2\u003e\n\u003cdiv class='rp-resource-details clearfix'\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eCurator Rating\u003c/dt\u003e\n\u003cdd\u003e\u003cspan class=\"star-rating\" aria-label=\"5.0 out of 5 stars\" role=\"img\"\u003e\u003ci class=\"fa-solid fa-star text-action\" aria-hidden=\"true\"\u003e\u003c/i\u003e\u003ci class=\"fa-solid fa-star text-action\" aria-hidden=\"true\"\u003e\u003c/i\u003e\u003ci class=\"fa-solid fa-star text-action\" aria-hidden=\"true\"\u003e\u003c/i\u003e\u003ci class=\"fa-solid fa-star text-action\" aria-hidden=\"true\"\u003e\u003c/i\u003e\u003ci class=\"fa-solid fa-star text-action\" aria-hidden=\"true\"\u003e\u003c/i\u003e\u003c/span\u003e\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt class=\"educator-rating-title\"\u003eEducator Rating\u003c/dt\u003e\u003cdd\u003e\u003cdiv class=\"educator-rating-details\" data-path=\"/educator_ratings/rrp_data?resourceable_id=188466\u0026amp;resourceable_type=Boclips%3A%3AVideoMetadata\"\u003e\u003cspan class=\"not-yet-rated\"\u003eNot yet Rated\u003c/span\u003e\u003c/div\u003e\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eMedia Length\u003c/dt\u003e\n\u003cdd\u003e2:25\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eGrade\u003c/dt\u003e\u003cdd title=\"Grade\"\u003e12th - Higher Ed\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eSubjects\u003c/dt\u003e\u003cdd\u003e\u003cspan\u003e\u003ca href=\"/search?grade_ids%5B%5D=258\u0026amp;grade_ids%5B%5D=259\u0026amp;search_tab_id=1\u0026amp;subject_ids%5B%5D=365221\"\u003eScience\u003c/a\u003e\u003c/span\u003e\u003c/dd\u003e\u003cdd class=\"text-muted\"\u003e\u003ci class=\"fa-solid fa-lock mr5\"\u003e\u003c/i\u003e10 more...\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eMedia Type\u003c/dt\u003e\u003cdd\u003e\u003cspan\u003e\u003ca href=\"/search?grade_ids%5B%5D=258\u0026amp;grade_ids%5B%5D=259\u0026amp;search_tab_id=2\u0026amp;type_ids%5B%5D=4543647\"\u003eInstructional Videos\u003c/a\u003e\u003c/span\u003e\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eSource:\u003c/dt\u003e\n\u003cdiv class='preview-source' data-animation='true' data-boundary='.rp-info' data-container='.rp-resource-details' data-html='false' data-title='Short, animated videos answering the big and small questions about the world around us.' data-trigger='hover focus'\u003e\n\u003cspan\u003eMinuteEarth\u003c/span\u003e\n\u003ci aria-hidden='true' class='fa-solid fa-circle-info channel-tooltip-icon' id='channel-tooltip'\u003e\u003c/i\u003e\n\u003c/div\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eDate\u003c/dt\u003e\n\u003cdd\u003e2018\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003ci aria-hidden='true' class='fai fa-solid fa-language'\u003e\u003c/i\u003e\n\u003cdt\u003eLanguage\u003c/dt\u003e\u003cdd\u003eEnglish\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eAudiences\u003c/dt\u003e\u003cdd\u003e\u003cspan\u003e\u003ca href=\"/search?audience_ids%5B%5D=371079\u0026amp;grade_ids%5B%5D=258\u0026amp;grade_ids%5B%5D=259\u0026amp;search_tab_id=1\"\u003eFor Teacher Use\u003c/a\u003e\u003c/span\u003e\u003c/dd\u003e\u003cdd class=\"text-muted\"\u003e\u003ci class=\"fa-solid fa-lock mr5\"\u003e\u003c/i\u003e2 more...\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eUsage Permissions\u003c/dt\u003e\u003cdd\u003eFine Print: Educational Use\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv aria-labelledby='additional-materials-heading' class='rp-info-section'\u003e\n\u003ch2 class='title' id='additional-materials-heading'\u003eAdditional Materials\u003c/h2\u003e\n\u003cdiv class='additional-material'\u003e\n\u003ci aria-hidden='true' class='fai fa-solid fa-lock'\u003e\u003c/i\u003e\n\u003ca class=\"text-muted\" title=\"Video Transcript\" data-html=\"true\" data-placement=\"bottom\" data-trigger=\"click\" data-content=\"\u003cdiv class=\u0026quot;text-center py-2\u0026quot;\u003e\u003ca class=\u0026quot;bold\u0026quot; href=\u0026quot;/auth/users/sign_in\u0026quot;\u003eSign in\u003c/a\u003e or \u003ca class=\u0026quot;bold text-danger\u0026quot; data-posthog-event=\u0026quot;Signup: LP Signup Activity\u0026quot; data-posthog-location=\u0026quot;body_link_boclips\u0026quot; data-remote=\u0026quot;true\u0026quot; href=\u0026quot;/subscription/new\u0026quot;\u003eJoin Now\u003c/a\u003e\u003c/div\u003e\" data-title=\"Get Full Access\" data-container=\"body\" rel=\"popover\" tabindex=\"0\" href=\"/subscription/new\"\u003eVideo Transcript\u003c/a\u003e\n\u003c/div\u003e\n\u003cdiv class='additional-material'\u003e\n\u003ci aria-hidden='true' class='fai fa-solid fa-lock'\u003e\u003c/i\u003e\n\u003ca class=\"text-muted\" title=\"Video Preview\" data-html=\"true\" data-placement=\"bottom\" data-trigger=\"click\" data-content=\"\u003cdiv class=\u0026quot;text-center py-2\u0026quot;\u003e\u003ca class=\u0026quot;bold\u0026quot; href=\u0026quot;/auth/users/sign_in\u0026quot;\u003eSign in\u003c/a\u003e or \u003ca class=\u0026quot;bold text-danger\u0026quot; data-posthog-event=\u0026quot;Signup: LP Signup Activity\u0026quot; data-posthog-location=\u0026quot;body_link_boclips\u0026quot; data-remote=\u0026quot;true\u0026quot; href=\u0026quot;/subscription/new\u0026quot;\u003eJoin Now\u003c/a\u003e\u003c/div\u003e\" data-title=\"Get Full Access\" data-container=\"body\" rel=\"popover\" tabindex=\"0\" href=\"/subscription/new\"\u003eVideo Preview\u003c/a\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv aria-labelledby='concepts-heading' class='rp-info-section'\u003e\n\u003ch2 class='title' id='concepts-heading'\u003eConcepts\u003c/h2\u003e\n\u003cdiv class='clearfix'\u003e\n\u003cdiv class='details-list concepts' data-identifier='Boclips::VideoDecorator5f871ccff015e06667da41cf' data-type='concepts'\u003edensity, venus, elevation, sea level, continents, area\u003c/div\u003e\n\u003cdiv class='concepts-toggle-buttons' data-identifier='Boclips::VideoDecorator5f871ccff015e06667da41cf'\u003e\n\u003cbutton aria-expanded='false' class='more btn-link' type='button'\u003e\n\u003cspan\u003eShow More\u003c/span\u003e\n\u003ci aria-hidden='true' class='fa-solid fa-caret-down ml5'\u003e\u003c/i\u003e\n\u003c/button\u003e\n\u003cbutton aria-expanded='true' class='less btn-link' style='display: none;' type='button'\u003e\n\u003cspan\u003eShow Less\u003c/span\u003e\n\u003ci aria-hidden='true' class='fa-solid fa-caret-up ml5'\u003e\u003c/i\u003e\n\u003c/button\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv aria-labelledby='additional-tags-heading' class='rp-info-section'\u003e\n\u003ch2 class='title' id='additional-tags-heading'\u003eAdditional Tags\u003c/h2\u003e\n\u003cdiv class='clearfix'\u003e\n\u003cdiv class='details-list keyterms' data-identifier='Boclips::VideoDecorator5f871ccff015e06667da41cf' data-type='keyterms'\u003ereason, crust, 000 feet, earth, middle, points, continental, average, continental crust, normal, denser, plates collide, bottom, dense, rock, high, planet surface, average elevation, ocean floor, elevations, planet, makes, ocean\u003c/div\u003e\n\u003cdiv class='keyterms-toggle-buttons' data-identifier='Boclips::VideoDecorator5f871ccff015e06667da41cf'\u003e\n\u003cbutton aria-expanded='false' class='more btn-link' type='button'\u003e\n\u003cspan\u003eShow More\u003c/span\u003e\n\u003ci aria-hidden='true' class='fa-solid fa-caret-down ml5'\u003e\u003c/i\u003e\n\u003c/button\u003e\n\u003cbutton aria-expanded='true' class='less btn-link' style='display: none;' type='button'\u003e\n\u003cspan\u003eShow Less\u003c/span\u003e\n\u003ci aria-hidden='true' class='fa-solid fa-caret-up ml5'\u003e\u003c/i\u003e\n\u003c/button\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv aria-labelledby='classroom-considerations-heading' class='rp-info-section'\u003e\n\u003ch2 class='title' id='classroom-considerations-heading'\u003eClassroom Considerations\u003c/h2\u003e\n\u003cdiv class='classroom-considerations'\u003e\u003cdiv class='fai fa-solid fa-bell'\u003e\u003c/div\u003eBest For: Explaining a topic\u003c/div\u003e\u003cdiv class='classroom-considerations'\u003e\u003cdiv class='fai fa-solid fa-bell'\u003e\u003c/div\u003eVideo is ad-free\u003c/div\u003e \n\u003c/div\u003e\n\u003cdiv aria-labelledby='educator-ratings-heading' class='rp-info-section'\u003e\n\u003ch2 class='title sr-only' id='educator-ratings-heading'\u003eEducator Ratings\u003c/h2\u003e\n\u003cdiv id=\"educator-ratings-root\"\u003e\u003c/div\u003e\u003cdiv id=\"all-educator-ratings-root\"\u003e\u003c/div\u003e\u003cdiv id=\"educator-rating-form-root\"\u003e\u003c/div\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv class='rp-resource'\u003e\n\u003cdiv aria-label='Show resource details' class='rp-show-info' role='button' tabindex='0'\u003e\n\u003ci class='fai fa-solid fa-align-left'\u003e\u003c/i\u003e\nShow resource details\n\u003c/div\u003e\n\u003cdiv aria-label='Video player' class='player' id='player-wrapper' role='region'\u003e\n\u003cdiv class='relative container mx-auto' id='lp-boclips-visitor-thumbnail'\u003e\n\u003ca class=\"block\" data-html=\"true\" data-placement=\"bottom\" data-trigger=\"click\" data-content=\"\u003cdiv class=\u0026quot;text-center py-2\u0026quot;\u003e\u003ca class=\u0026quot;bold\u0026quot; href=\u0026quot;/auth/users/sign_in\u0026quot;\u003eSign in\u003c/a\u003e or \u003ca class=\u0026quot;bold text-danger\u0026quot; data-posthog-event=\u0026quot;Signup: LP Signup Activity\u0026quot; data-posthog-location=\u0026quot;body_link_boclips\u0026quot; data-remote=\u0026quot;true\u0026quot; href=\u0026quot;/subscription/new\u0026quot;\u003eJoin Now\u003c/a\u003e\u003c/div\u003e\" data-title=\"Get Full Access\" data-container=\"body\" rel=\"popover\" tabindex=\"0\" aria-label=\"Play video: Why Earth Has Two Levels\" href=\"/subscription/new\"\u003e\u003cimg class=\"resource-img img-thumbnail img-responsive z-10 lp-boclips-thumbnail w-full h-full lozad\" alt=\"Why Earth Has Two Levels\" title=\"Why Earth Has Two Levels\" onError=\"handleImageNotLoadedError(this)\" data-default-image=\"https://static.lp.lexp.cloud/images/attachment_defaults/resource/large/missing.png\" data-src=\"https://cdnapisec.kaltura.com/p/1776261/thumbnail/entry_id/1_7sc7vuuo/width/250/vid_slices/3/vid_slice/1\" width=\"315\" height=\"220\" src=\"data:image/png;base64,R0lGODlhAQABAAD/ACwAAAAAAQABAAACADs\" /\u003e\n\u003cspan aria-hidden='true' class='flex justify-center items-center bg-white rounded-full w-16 h-16 absolute top-1/2 left-1/2 -mt-8 -ml-8 cursor-pointer z-0 border-2 border-primary drop-shadow-md lp-boclips-thumbnail-playBtn'\u003e\n\u003ci class='fa-solid fa-play text-primary text-3xl ml-1 drop-shadow-xl'\u003e\u003c/i\u003e\n\u003c/span\u003e\n\u003c/a\u003e\u003c/div\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n"}