Earthquakes, Volcanoes and Tsunamis: Causes and Effects — Answers
Answer sheet with model answers and success criteria for the 6th Grade earth, rocks & weather worksheet.
Success TutoringWorksheetsAnswer sheet6th Grade · Science · Earth, Rocks & WeatherEarthquakes, Volcanoes and Tsunamis: Causes and Effects — Answers
Part A: Moving plates
Read the passage, then answer the questions.
The Earth's outer layer, the crust, is broken into huge pieces called tectonic plates. They float on hot, partly melted rock and move very slowly — only a few centimeters each year, about as fast as your fingernails grow.
Where plates meet, their edges can lock together. Pressure builds up until the rock suddenly slips. The energy released travels through the ground as waves, causing an earthquake.
Deep underground it is hot enough to melt rock into magma. Magma can rise through cracks in the crust. When it erupts from a volcano it is called lava, and it can come with ash and gases.
- Astrong winds pushing on mountains
- Btectonic plates that get stuck and then suddenly slip
- Cheavy rain soaking into the ground
- Dthe Moon pulling on the land
Answer: tectonic plates that get stuck and then suddenly slip
Plates are always moving slowly. When their edges lock together, pressure builds until the rock suddenly slips, shaking the ground.
- Ain the middle of plates
- Bnear the edges of tectonic plates
- Conly near the North Pole
- Donly in deserts
Answer: near the edges of tectonic plates
Plate edges are where plates push together, pull apart or slide past each other, so that is where most activity happens.
- Amelted rock under the ground
- Bcooled rock on the surface
- Cvolcanic ash in the air
- Da type of earthquake wave
Answer: melted rock under the ground
Magma is melted rock below the surface. When it comes out of a volcano it is called lava.
- Aa thermometer
- Ba rain gauge
- Ca seismometer
- Da barometer
Answer: a seismometer
A seismometer detects and records ground movement.
Answer: plates
Answer: lava
Part B: Tsunamis and staying safe
Match the words, then write True or False.
When an earthquake happens under the sea, the sea floor can suddenly lift or drop, pushing a huge amount of water. This makes a tsunami. In deep ocean the waves are low but move as fast as a jet plane. As they reach shallow water near the coast they slow down and grow very tall.
Warning centers use seismometers and ocean sensors to detect earthquakes and tsunamis and send out alerts. Scientists also watch volcanoes for small earthquakes, swelling ground and gas, which can be signs an eruption is coming.
- epicenter
- tsunami
- eruption
- aftershock
- when magma, ash and gases burst out of a volcano
- the point on the surface directly above where an earthquake starts
- a smaller earthquake that follows a large one
- a series of huge ocean waves caused by a sudden movement of the sea floor
Answer: epicenter → the point on the surface directly above where an earthquake starts; tsunami → a series of huge ocean waves caused by a sudden movement of the sea floor; eruption → when magma, ash and gases burst out of a volcano; aftershock → a smaller earthquake that follows a large one
Answer: False
Tsunamis are usually caused by undersea earthquakes (or landslides and eruptions) that suddenly move a huge amount of water. Wind makes ordinary waves.
Answer: True
This can be a natural warning that a tsunami is coming.
Answer: True
"Drop, Cover and Hold On" protects you from falling objects.
Answer: False
Scientists can say which areas are at risk, but they cannot yet predict exactly when an earthquake will happen.
Part C: Apply it
Answer: 2 hours
- time = distance ÷ speed
- 1400 ÷ 700 = 2 hours
Answer: It gives them time to receive a warning and move to high ground or inland before the waves arrive.
Answer: Any one of: strong flexible frames (e.g. steel), deep foundations, bracing walls, bases that absorb shaking, securing heavy furniture.
Model answer: 1. Set up a tsunami warning system with sirens and phone alerts, so people know to leave as soon as a large undersea earthquake is detected. 2. Mark evacuation routes to high ground and practice them, so people know where to go quickly. 3. Build or strengthen buildings to withstand shaking, so they are less likely to collapse. 4. Teach Drop, Cover and Hold On in schools, so people protect themselves from falling objects. 5. Keep emergency kits with water, food, a radio and first aid, in case services stop working.
Success criteria:
- At least three sensible preparation actions
- Each action linked to how it keeps people safe
- Covers both earthquakes and tsunamis
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.
Great work. Here's what to try next: