All earthquakes

Earthquakes in 1977

The USGS located 3,580 earthquakes of magnitude 4.5 or more worldwide in 1977, 85 of them magnitude 6 or more, and 2,509 of magnitude 2.5 or more in the United States. The largest: M8.3 1977 Sumba, Indonesia Earthquake, Aug 19, 1977.

From the USGS catalog. Magnitude 4.5 and up worldwide, and 2.5 and up in the United States. Times are local to each quake.

19761978

Map

Where the largest earthquakes of 1977 were located. Select one for its page.

Open the live map with earthquakes

The largest

The 25 largest of 1977, by magnitude.

Month by month

Counted by UTC date, which is how the catalog files them.

MonthQuakesLargestWhere
January 19775326.663 km NE of Angoram, Papua New Guinea
February 19774516.7225 km WNW of Attu Station, Alaska
March 19775237.52 km N of Spulber, Romania
April 19774957.6199 km ESE of Hihifo, Tonga
May 19774256.080 km SW of Nikolski, Alaska
June 19774346.8Tonga region
July 19774017.2143 km W of Gizo, Solomon Islands
August 19774998.31977 Sumba, Indonesia Earthquake
September 19776126.6Rat Islands, Aleutian Islands, Alaska
October 19775307.2south of Tonga
November 19775297.4San Juan, Argentina
December 19774166.8Volcano Islands, Japan region

By state

Where the year’s United States quakes of magnitude 2.5 and up were located. A state with none that year is not listed.

By country

Where the year’s quakes of magnitude 4.5 and up were located. Quakes at sea, away from any country, are not counted here.

What this means

The catalog is only as complete as the instruments of the time. Worldwide coverage of magnitude 5 and up dates from the 1960s, and of 4.5 from the 1990s; earlier years hold the large quakes and the ones near a station, so a low count in an early year means fewer instruments, not a quiet earth.

By year

Every year the USGS catalog covers.

Sources

Earthquakes, magnitudes, depths, shaking estimates and felt reports from the U.S. Geological Survey Earthquake Hazards Program, read from its live feeds and its catalog back to 1900. Tsunami messages from NOAA’s tsunami warning centers.