What forms at each kind of plate boundary
Grade 9 Science Worksheet - Building Confidence
Circle the best answer.
Station A moves west at 2 cm a year. Station B moves east at 2 cm a year. Station A lies west of a boundary and Station B lies east of it. What boundary lies between them, by Ari's reading?
- Divergent: the stations move apart by 2 cm a year
- Convergent: the stations move together by 4 cm a year
- Divergent: the stations move apart by 4 cm a year
- Transform: the stations slide past each other by 4 cm a year
Station A moves east at 3 cm a year. Station B moves west at 2 cm a year. Station A lies west of a boundary and Station B lies east of it. What boundary lies between them, by Bo's reading?
- Divergent: the stations move apart by 5 cm a year
- Convergent: the stations close in by 1 cm a year
- Transform: the stations slide past each other by 5 cm a year
- Convergent: the stations close in by 5 cm a year
Read this first
Card (example data)
Station N moves east at 3 cm a year. Station S moves west at 3 cm a year. The distance between them does not change.
A boundary runs east to west. Station N lies north of it and Station S lies south of it. What boundary is it, by Kira's reading?
- Convergent: the plates move together, so crust is recycled along the boundary between them
- Transform: the plates slide past each other, and no crust is made or recycled
- Divergent: the plates slide past each other, and that is how new crust forms there
- Divergent: the plates move apart, so new crust forms along the boundary between them
Card (example data)
Sea-floor rock is youngest in the central valley and gets older on both sides. Plates on each side move away from the valley.
A sonar survey crosses a mid-ocean valley. What boundary and process explain the pattern, by Jun's reading?
- A divergent boundary, where new crust forms along the valley
- A transform boundary, where plates slide past along the valley
- A convergent boundary, where old crust is recycled along the valley
- A hotspot, where a plume builds a ridge inside the plate
When two continents meet head-on, neither subducts. Continental crust is light and buckles upward. India and Asia are both continental plates. Which statement about their meeting fits the card, by Luz's reading?
- Asia sinks under India, forming a deep trench beside the new mountain range
- India sinks under Asia, forming a deep trench and a volcanic arc along the range
- Neither plate sinks; the light crust buckles up into the Himalayas
- The plates part, and a rift valley forms between the two continents in the middle
Transform faults offset ridges, plates slide past each other there, and earthquakes are shallow. A map shows a ridge cut into offset pieces by cracks at right angles to it. What are the cracks, by Milo's reading?
- New ridges, where the sliding plates make new crust between the offset pieces
- Transform faults, where plates slide past with shallow earthquakes
- Trenches, where plates sink and crust is recycled along each offset piece
- Hotspot tracks, where volcanoes line up inside a plate away from the ridge
The vast majority of earthquakes and volcanoes occur near plate boundaries. Hotspots are long-lasting hot regions below plates. Hawaii formed more than 3,200 km from the nearest plate boundary. What explains its volcanoes, by Noah's reading?
- A nearby divergent boundary right under the islands, where two plates part
- A hotspot: a long-lasting hot region below the plate
- A nearby convergent boundary right under the islands, where one plate sinks
- A transform fault that crosses the islands, where two plates slide past
Card (USGS)
The vast majority of earthquakes and volcanoes occur near plate boundaries. Hawaii formed more than 3,200 km from the nearest boundary.
Which statement about where volcanoes occur fits the card, by Ren's reading?
- Volcanoes occur on boundaries without exception, and Hawaii is a boundary
- Volcanoes occur far from boundaries, and boundaries have few of them
- Volcanoes occur near boundaries, and hotspots are boundaries too
- Most are near boundaries, and hotspots explain exceptions such as Hawaii
Earthquake depths across a trench (example data)
Distance inland from trench Depth 0 km 10 km 50 km 60 km 100 km 110 km 150 km 160 km Tala reads the table. What pattern do the earthquake depths show?
- They stay near 10 km at each distance, tracing a flat fault under the land
- They are deepest at the trench and shallow inland, tracing a plate rising
- They get deeper farther inland, tracing a plate sinking beneath
- They get shallower farther inland, tracing a plate that rises as it goes
At subduction zones, earthquakes lie in a zone sloping down under the overriding plate and reaching several hundred km. A map shows shallow quakes at a trench and deep quakes 300 km inland. Which boundary fits, by Zee's reading?
- A hotspot, where a plume rises under a plate
- Convergent, where one plate sinks under another
- Divergent, where plates part and crust is made
- Transform, where plates slide past at the surface