Earthquakes and volcanoes

Natural hazards caused by tectonic activity at plate boundaries

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Try each question. If you're stuck, leave it and come back. The answer key is on the last page.

1
Where do most earthquakes happen? A) Along tectonic plate boundaries B) In the middle of oceans only C) In deserts D) Only in cold countries
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2
True or false? A dormant volcano is one that has not erupted for a long time but could erupt again. A) True B) False
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3
Fill in the blank. The strength of an earthquake is measured on the ___ scale.
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4
True or false? A volcano erupts when magma is pushed up to the surface. A) True B) False
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5
What is the Ring of Fire? A) A zone around the Pacific Ocean with many volcanoes and earthquakes B) A type of erupting volcano C) An ancient volcano in Africa D) A volcano on the Moon
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6
Match each volcano to its country. Match each item on the left to one on the right. Left: Vesuvius, Etna, Krakatoa, Mount St Helens Right: Italy, Italy, Indonesia, USA
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7
Hot, liquid rock inside a volcano is called... A) Magma B) Lava C) Pumice D) Ash
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8
Complete the sentence. The point on the Earth's surface directly above where an earthquake starts is called the ___.
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9
Which statement about magma and lava is correct? A) Magma is inside the Earth, lava is on the surface B) Lava is hotter than magma C) Magma comes only from extinct volcanoes D) Lava and magma are completely different materials
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10
Order these events during a volcanic eruption. Put these in order: Lava flows or ash is thrown into the air, Magma rises through the volcano, Pressure builds inside the Earth, Magma collects in a chamber
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Answer key

Earthquakes and volcanoes · for parents and teachers

1
Along tectonic plate boundaries
Most earthquakes happen near tectonic plate boundaries, where stresses build up as plates push, pull or slide against each other.
2
True
Volcanoes are classified as active (recently erupted or erupting), dormant (could erupt again but not for a long time), or extinct (will not erupt again).
3
Richter
The Richter scale measures the strength (magnitude) of an earthquake. The scale is logarithmic, so each step up is 10 times more powerful than the one below.
4
True
True. Volcanoes erupt when pressure forces magma up through the crust.
5
A zone around the Pacific Ocean with many volcanoes and earthquakes
The Ring of Fire is a horseshoe-shaped zone around the Pacific Ocean. About 75 per cent of the world's volcanoes are found here, where many tectonic plates meet.
6
Vesuvius → Italy; Etna → Italy; Krakatoa → Indonesia; Mount St Helens → USA
Vesuvius and Etna are in Italy, with Vesuvius famous for destroying Pompeii in 79 AD. Krakatoa is in Indonesia and Mount St Helens is in the USA.
7
Magma
Inside the Earth, molten rock is called magma. Once it erupts and reaches the surface, the same material is called lava.
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epicentre
The epicentre is the point on the Earth's surface directly above the earthquake's origin (the focus, deep underground). Damage is usually greatest near the epicentre.
9
Magma is inside the Earth, lava is on the surface
Magma and lava are the same molten rock. We call it magma when it is inside the Earth, and lava once it erupts onto the surface.
10
Pressure builds inside the Earth, Magma collects in a chamber, Magma rises through the volcano, Lava flows or ash is thrown into the air
Eruptions begin with pressure deep underground, forcing magma into a chamber and then up through the volcano. When it reaches the surface, lava and ash erupt out.