Start of the Eruption: 1983
Map of topographic, volcanic, and cultural features of the East Rift Zone
and south flank of Kilauea volcano. Modified from Clague and Heliker (1992).
| 1. Kilauea caldera | 6. Kamoamoa | 11. Highway 130 |
| 2. Chain of Craters Road | 7. Wahaula | 12. Highway 11 |
| 3. Puu Oo | 8. Lae Apuki | 13. Pauahi Crater |
| 4. Kupaianaha | 9. Kapaahu | 14. Mauna Ulu |
| 5. Royal Gardens | 10. Kalapana |
On the early morning of January 2, 1983, the summit of Kilauea began
to deflate, and the number and size of earthquakes increased in the
volcano's east rift zone. The earthquakes started near Mauna Ulu and
migrated down right to Napau Crater and Puu Kamoamoa.
Geologists interpreted the swarm of earthquakes to be a result of magma
breaking rock as it is forced into the rift zone and then moved towards
the surface.
Shortly after midnight on January 3, 1983, lava was sighted near
Napau Crater.
Seismic instruments also recorded an increase in the amount of harmonic
tremor, the earthquake pattern that indicates magma movement and
eruption. Over the next nine hours, a discontinuous line of the eruptive
fissures
extended 4 miles (6 km) down the rift (see above photo).
Near the end of this activity the eruption became concentrated in the
vicinity of Puu Kamoamoa. Subsequent eruptive activity was located at
several different vents and varied in duration from less than an hour to
almost one day. The photograph shows a line of fissures about 0.9 km
long. Lava flows are extending to the north and south. View is to the
southeast. Photograph by J.D. Griggs, U.S. Geological Survey, January 3,
1983, 7:29 a.m.
Geologists from the U.S. Geological Survey's Hawaiian Volcano Observatory
monitored the eruption in many ways. This photo shows a geologist
approaching a fissure to collect a sample of
spatter
for chemical analysis. Photograph by J.D. Griggs, U.S.
Geological Survey, January 7, 1983.
Change to Central-Vent Eruptions
Episode 2 of the eruption began on February 10, and continued to March
4. The primary eruption site was then a
central vent,
rather than a series of fissures. This vent was called the 1123 vent, a
name designated at the time of its first eruptive activity. Lava
fountains from this vent reached a height of 260 ft (80 m). Episode 3
(March 21 to April 9, 1983) was also located at the 1123 vent. This
episode had two
lava fountains, one of which attained a
height of 650 ft (200 m) near the end of the episode. The second, lower
fountain, fed an
aa
lava
flow that
extended 4.4 miles (7 km) to the southeast and reached the Royal Gardens
subdivision. Photograph by J.P. Lockwood, U.S. Geological Survey, April
3, 1983.
