Card 1
HintThink about the total percentage of the Earth's surface.Memory Tip7-1, mostly water.
Card 2
HintThink about the five main oceans on a world map.Memory TipPAISA: Pacific, Atlantic, Indian, Southern, Arctic.
Card 3
HintIt covers more than half of Earth's water.Memory TipPacific: Plenty of space.
Card 4
HintIt's roughly four times deeper than average land elevation.Memory TipAverage depth: 3.8 km.
Card 5
HintIt's where land meets the deep ocean.Memory TipMargin: where two areas meet.
Card 6
HintThink about coastlines with a lot of earthquakes and volcanoes.Memory TipActive means plate boundary.
Card 7
HintThink of calm, stable coastlines like the east coast of the US.Memory TipPassive means no plate action.
Card 8
HintIt's the underwater extension of the landmass, relatively flat.Memory TipShelf: shallow edge.
Card 9
HintIt's after the shelf, going down.Memory TipSlope: downward angle.
Card 10
HintIt's the ultimate deep, flat part of the ocean.Memory TipAbyssal: flat, deep, vast.
Card 11
HintIt's like topography, but for underwater.Memory TipBath = depth.
Card 12
HintThink of old sailors and ropes.Memory TipSounding: dropping a line.
Card 13
HintIt's an old nautical measurement based on human reach.Memory TipFathom: six feet.
Card 14
HintThink of bats using sound to navigate.Memory TipEcho: sound for depth.
Card 15
HintThey measure the ocean's surface to infer what's below.Memory TipSatellite: measures surface bumps.