Chart assignment

Charts to read and discuss

Read each chart, then answer its questions. Every chart shows its source and date; open it for a table of the numbers and the data to download.

  1. How many visits does the whole National Park System get each year?
  2. How much rarer is each step up in earthquake magnitude?

Chart 1 of 2 · National parks

How many visits does the whole National Park System get each year?

The interactive chart needs JavaScript. The numbers are on the chart's page.

All the sites the National Park Service runs, from national parks to monuments, parkways, seashores and memorials, had 323 million recreation visits in 2025, against the record 332 million of 2024 and 205 million in 1979. Part of the rise comes from new sites: about 270 reported visits in 1979 and 400 in 2025. The 2020 dip to 237 million came from pandemic closures.

Questions to discuss

  1. In one sentence of your own, what does this chart show?
  2. Find the biggest change or difference in the chart. What might explain it?
  3. Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?

Source: National Park Service, Visitor Use Statistics (Public domain (U.S. government work); source National Park Service) · Data as of Dec 31, 2025

Open the chart and its numbers

Chart 2 of 2 · Earthquakes

How much rarer is each step up in earthquake magnitude?

The interactive chart needs JavaScript. The numbers are on the chart's page.

In 2025 the world recorded 6,428 earthquakes of magnitude 4.5 to 4.9, 1,983 of magnitude 5, 129 of magnitude 6, 15 of magnitude 7 and 1 of magnitude 8 or more. Each step up in magnitude is roughly ten times rarer, and releases about 32 times more energy. Countless smaller quakes go unrecorded worldwide, so the chart starts at 4.5.

How to read this chart

Each bar counts the earthquakes recorded worldwide in one year within a range of magnitudes. The bars start at zero. Each whole step up in magnitude releases about 32 times more energy, so a magnitude 7 quake is far more than one step stronger than a 6.

Questions to discuss

  1. Roughly how many times more common is each band than the one above it?
  2. The biggest bars are hard to compare with the smallest ones on this scale. What other way could you show these numbers?
  3. The chart starts at magnitude 4.5. Why might smaller earthquakes around the world go uncounted?

Source: U.S. Geological Survey, ANSS Comprehensive Earthquake Catalog (ComCat) (Public domain (U.S. government work); source U.S. Geological Survey) · Data as of Dec 31, 2025

Open the chart and its numbers

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