2-ESS1-1: Fast and Slow Changes to Earth
Also called NGSS 2-ESS1-1 · Topic: Earth's Systems: Processes that Shape the Earth · Earth and Space Science
The Official Wording
Use information from several sources to provide evidence that Earth events can occur quickly or slowly.
Clarification statement: Examples of events and timescales could include volcanic explosions and earthquakes, which happen quickly and erosion of rocks, which occurs slowly.
Assessment boundary: Assessment does not include quantitative measurements of timescales.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What 2-ESS1-1 Means in Plain English
Second graders use books, photos, videos and maps to gather evidence that some changes to Earth's surface happen in minutes or hours, like a landslide or an earthquake, while others take a very long time, like a river slowly carving a canyon.
Students compare fast and slow in everyday terms and do not measure or calculate how long events take. In 4th grade they read rock layers for clues about past changes (4-ESS1-1) and study how water, ice and wind wear rock away (4-ESS2-1).
2-ESS1-1 I Can Statements
- I can find facts about Earth changes in books and pictures.
- I can sort Earth events into fast changes and slow changes.
- I can use evidence from more than one source.
2-ESS1-1 Worked Example
A class sorting line built from event cards, short readings and a few photos.
Do changes to Earth's land happen quickly, slowly, or both?
Set It Up: Six picture cards with short readings about a landslide, an earthquake, a volcano eruption, a canyon, a creeping sand dune and a rock arch, plus a clothesline and clothespins.
- Read each card with a partner and underline time words like minutes, years or long ago.Time clues underlined
- Check one more source for each event, like a photo pair or a short video clip.Two sources per event
- Clip each card on the line, fast end on the left and slow end on the right.Landslide, earthquake, eruption at the fast end
- Place the canyon, the dune and the arch.Canyon, dune and arch at the slow end
- Explain one placement using a fact from each source.Two facts back up each spot
Some events reshape land in minutes, while others, like a river cutting a canyon, take far longer than a human lifetime.
Why it works: Sudden events release a lot of energy at once, while wind and water wear rock away a tiny bit at a time over very long periods.
Common Mistakes with 2-ESS1-1
Thinking all big changes are fast
“The canyon is huge, so it must have happened fast”
Try this: Size does not tell speed. Look for time clues in the sources, like how much a place changed between old and new photos.
Thinking slow changes are not happening
“Rocks never change”
Try this: Slow changes are happening all the time, just too slowly to notice in a day. Compare photos taken many years apart.
Relying on one source
Placing every card from the picture alone
Try this: Back up each placement with a second source, like a reading or video, before deciding whether the change is fast or slow.
Where 2-ESS1-1 Fits
Practice 2-ESS1-1
Quick Check
- Is an earthquake a fast or slow change?
- How did a river make a deep canyon?
- Why check more than one source?