Kilauea earthquakes and eruptions: Amazing animation shows 100 days of activity at Kilauea Volcano in Hawaii
That was just awesome!
The NWS’s Pacific Tsunami Warning Center (PTWC) mitigates tsunami
hazards in Hawai‘i produced by large, distant earthquakes throughout the
Pacific Ocean, but PTWC also issues warnings for tsunamis generated by
earthquakes within the State of Hawai‘i itself. The last such dangerous
tsunami was generated by a 7.7 magnitude earthquake on the Big Island of
Hawai‘i in 1975. Small earthquakes generated by volcanic activity are
far more common, and typically have a magnitude less than 3.0 and occur a
few times a day. That rate changed on the afternoon of April 30, 2018,
when an earthquake “swarm” began within Kīlauea Volcano such that
earthquakes began to occur far more frequently, about 100 per day.
Kilauea volcanic eruption video. via Youtube
This animation begins a month earlier on April 1 to start with a more
typical earthquake pattern and proceeds forward in time at a rate of
one day per second of animation time. Circles indicate the location of
earthquakes as they occur, with their size indicating their magnitude
and their color representing their depth. Three days before the swarm
began the lava within the “Overlook crater” inside of Halema‘uma‘u
overflowed. Then on April 30 the 35-year-old Puʻu ʻŌʻō eruption ceased
and its cone partially collapsed. This event coincided with the start of
a swarm of volcanic earthquakes on Kilauea’s East Rift Zone, a feature
extending from the volcano’s summit that carries magma underground
through its flanks. Eruptions can take place anywhere along this rift
zone as well as at the volcano’s summit. Earthquake occurrence then
moved northeast along the East Rift Zone away from the summit,
suggesting the movement of magma below ground in this direction. Magma
reached the surface and erupted as lava on the afternoon of May 3,
eventually building channelized lava flows, destroying about 700 homes,
and covering more than 12 square miles including Kapoho Bay. In this
animation a growing orange field represents these lava flows.
Kilauea volcanic eruption video. via Youtube
Lava began to drain from the “Overlook crater” at the same time and
by May 15 its lava lake had dropped hundreds of feet before producing
steam-driven explosions when it interacted with ground water. Some of
these explosions were strong enough to register as magnitude 5.0
earthquakes and sent ash clouds to 30,000 ft. above sea level. By the
end of May, however, these explosions changed their character such that
they no longer produced large steam-driven ash clouds. The walls of
Halema‘uma‘u had begun to collapse, thus widening it and burying its
“Overlook crater” as magma continued to drain from the summit to feed
the flank eruption. These “collapse explosions” seemed to release
trapped volcanic gas rather than groundwater steam and yielded only
small ash clouds, though they still released explosive energy greater
than magnitude 5.0 earthquakes and occurred about once per day. In this
animation black circles represent these volcanic explosions with their
size indicating their energy release in equivalent earthquake magnitude.
No explosions have occurred since August 2 but it is too early to tell
whether similar explosions will happen again.
Kilauea volcanic eruption video. via Youtube
This animation includes charts showing some statistics about the
earthquake activity. The top graph shows the maximum earthquake
magnitude per day. The bottom graph shows the total number of
earthquakes per day. On April 30 the frequency of earthquakes increased
to about 100 per day and their magnitudes exceeded magnitude 4.0. The
largest earthquake struck on the afternoon of May 4 with a magnitude of
6.9 that produced numerous aftershocks that continue today. This largest
earthquake also moved the flank of Kilauea Volcano as much as 20 inches
seaward. With the subsidence of Kilauea Caldera and the collapse of
Halema‘uma‘u the number of earthquakes dramatically increased to more
than 700 per day by June 15 and continued until August 4 when they
suddenly returned to normal background levels, coinciding with the pause
of the vigorous eruption of lava.
Kilauea volcanic eruption video. via YoutubeKilauea volcanic eruption video. via Youtube
Though PTWC monitors all earthquakes in Hawaii, including this
ongoing activity, the primary responsibility for mitigating volcanic
hazards in the State of Hawaii rests with the USGS’s Hawaiian Volcano
Observatory who publishes updates daily and advises local emergency
managers.
Be ready! Get prepared!
http://strangesounds.org/2018/09/kilauea-earthquakes-and-eruptions-amazing-animation-shows-100-days-of-activity-at-kilauea-volcano-in-hawaii.html
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