Polynesian settlers, who first reached Hawai`i about 1500 years ago, preserved almost no record of Mauna Loa's eruptive activity, and the earliest references are fragmentary accounts of activity in the late 18th and 19th centuries. The first extended written account of a Mauna Loa eruption was by a missionary who witnessed the June 1832 eruption from Maui, 190 km away; the lava flows erupted during this activity have not yet been positively identified, however, so this eruption is not included in the eruption-summary table below.
Want to learn more about the eruptions listed in the table?
Follow the links of each "year" for an eruption chronology, photos and map showing areas covered by lava and early eyewitness accounts of Mauna Loa's eruptions.
| Year | Start (mo-day) | Summit (days) |
Flank (days) | Eruptive Subdivision | Area Covered (km2) | Volume (km3 | Error in Estimated Volume (%) |
|---|---|---|---|---|---|---|---|
| 1984 | Mar-25 | <1 | 22 | S, NE | 48 | 0.220 | ?20 |
| 1975 | Jul-5 | 1 | 0 | S | 13 | 0.030 | ?20 |
| 1950 | Jun-1 | 1 | 23 | S, SW | 112 | 0.376 | ?20-40 |
| 1949 | Jan-6 | 145 | 0 | S | 22 | 0.116 | ?20 |
| 1942 | Apr-26 | 2 | 13 | S, NE | 34 | 0.176 | ?20 |
| 1940 | Apr-17 | 134 | 0 | S | 13 | 0.110 | ?20 |
| 1935 | Nov-21 | 6 | 40 | S, NE, MKN | 33 | 0.087 | ?20-40 |
| 1933 | Dec-2 | 17 | 0 | S | 6 | 0.100 | ?20-40 |
| 1926 | Apr-10 | <1 | 14 | S, SW | 35 | 0.121 | ?20-40 |
| 1919 | Sep-26 | <1 | 38 | S, SW | 28 | 0.183 | ?20-40 |
| 1916 | May-19 | 0 | 12 | SW | 17 | 0.031 | ?20-40 |
| 1914 | Nov-25 | 48 | 0 | S | 5 | 0.055 | ?20-40 |
| 1907 | Jan-9 | <1 | 15 | S, SW | 28 | 0.121 | ?20-40 |
| 1903 | Oct-6 | 61 | 0 | S | 5 | 0.070 | > ?40 |
| 1903 | Sep-1 | <1 | 0 | S | 1 | 0.003 | no data |
| 1899 | Jul-1 | 4 | 21 | S, NE | 23 | 0.081 | ?20-40 |
| 1896 | Apr-21 | 16 | 0 | S | 5 | 0.025 | > ?40 |
| 1892 | Nov-30 | 3 | 0 | S | 3 | 0.012 | > ?40 |
| 1887 | Jan-16 | <1 | 7 | S, SW | 29 | 0.128 | ?20-40 |
| 1880 | Nov-5 | 0 | 280 | NE | 51 | 0.130 | ?20-40 |
| 1880 | May-1 | 6 | 0 | S | 5 | 0.010 | no data |
| 1879 | Mar-9 | S | 0 | 1 | 0.001 | no data | |
| 1877 | Feb-14 | < | <1 | S, MKN | 1 | 0.008 | > ?40 |
| 1872 | Aug-9 | ~1,200 (nearly continuous) |
0 | S | 5 | 0.630 | ?20-40 |
| 1871 | Aug-10 | ~20 | 0 | S | 3 | 0.020 | no data |
| 1868 | Mar-27 | <1 | 5 | S, SW | 24 | 0.123 | ?20-40 |
| 1865 | Dec-30 | ~125 | 0 | S | 5 | 0.050 | no data |
| 1859 | Jan-23 | <1 | ~300 | S, MKN | 91 | 0.383 | > ?40 |
| 1855 | Aug-8 | <1 | ~450 | S, NE | 66 | 0.280 | > ?40 |
| 1852 | Feb-17 | 1 | 20 | S, NE | 33 | 0.182 | ?20-40 |
| 1851 | Aug-8 | 4 | 0 | S | 12 | 0.035 | ?20-40 |
| 1849 | May-(?) | 15 | 0 | S | 5 | 0.025 | no data |
| 1843 | Jan-10 | 5 | ~90 | S, NE, MKN | 45 | 0.202 | > ?40 |
| Total | 806 km2 | 4.124 km3 |
Other sources list as many as seven eruptions between 1872 and 1876; this table refers to the extended eruptive activity as one eruptive episode following the authors (below).
Eruptive subdivisions include the summit area (S) which consists of vent locations above 3,660 m; (SW) southwest rift zone; (NE) northeast rift zone; and (MKN) north of Moku`aweoweo Caldera. The number of historical eruptions and average rates of lava eruption for each subdivision are shown on this map.
Descriptions of the following eruptions appear in Life in Hawai`i by Rev. Titus Coan, published in 1882 and presented online by The Hawai`i Center for Volcanology.
| 1843 | 1852 | 1855-1856 | 1868 & 1877 | Nov 1880 |
