Earthquakes
Grade 4 · Science · Earth's Changing Surface · Arkansas, USA
Lesson Summary
Earthquakes happen when large pieces of Earth's crust suddenly move. The shaking can change the surface in seconds.
Explanation
The outer layer of Earth is broken into big pieces called tectonic plates. These plates float slowly on hot, melted rock below. When plates push against, pull apart from, or slide past each other, stress builds up. When the stress is released suddenly, the ground shakes. This is an earthquake. The point underground where the earthquake starts is called the focus, and the spot on the surface right above it is the epicenter. Scientists use a seismograph to measure how strong an earthquake is.
Practice Questions
Q1: What causes earthquakes?
Answer: Earthquakes are caused by the sudden release of stress where tectonic plates meet.
Q2: What is the difference between the focus and the epicenter?
Answer: The focus is the point underground where the earthquake starts. The epicenter is the point on the surface directly above the focus.
Q3: What instrument do scientists use to measure earthquakes?
Answer: A seismograph.
People Also Ask
What is Earthquakes in Grade 4 Science?+
Earthquakes is a lesson in the Earth's Changing Surface chapter of Grade 4 Science. It is part of the Arkansas, USA school curriculum and covers key concepts that students need to understand at this level.
What grade level covers Earthquakes?+
Earthquakes is taught in Grade 4 as part of the Science curriculum in Arkansas, USA.
How can I help my child with Earth's Changing Surface in Science?+
Start with the lesson summary and explanation on this page. Practice the questions provided, then use TutorTom for personalized, step-by-step help with Earth's Changing Surface topics.