Shake intensity

Note: Map shows the area with a shake intensity of 4 or greater, which U.S.G.S. defines as “light,” though the earthquake may be felt outside the areas shown. The New York Times

Two strong earthquakes were among a series of tremors that shook Taiwan's eastern coast early Tuesday local time. No injuries or deaths had been reported by Tuesday morning.

The quakes damaged buildings in an area struck by a larger earthquake that killed 17 people earlier this month and were considered aftershocks of the earlier quake, authorities said.

National agencies often report different strengths for a quake. Taiwanese officials reported Tuesday’s largest quake as a magnitude 6.3, while the United States Geological Survey said its magnitude was 6.1.

As seismologists review available data, they may revise the earthquakes’ reported magnitude. Additional information collected about the earthquake may also prompt U.S.G.S. scientists to update the shake-severity maps.

Aftershocks in the region

An aftershock is usually a smaller earthquake that follows a larger one in the same general area. Aftershocks are typically minor adjustments along the portion of a fault that slipped at the time of the initial earthquake.

Quakes and aftershocks within 100 miles

Aftershocks can occur days, weeks or even years after the first earthquake. These events can be of equal or larger magnitude to the initial earthquake, and they can continue to affect already damaged locations.

Source: United States Geological Survey | Notes: Shaking categories are based on the Modified Mercalli Intensity scale. When aftershock data is available, the corresponding maps and charts include earthquakes within 100 miles and seven days of the initial quake. All times above are Taipei time. Shake data is as of Monday, April 22 at 2:46 p.m. Eastern. Aftershocks data is as of Friday, April 26 at 2:41 a.m. Eastern.