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Hawaiian Acres
Pāhoa
Wao Kele o Puna Kaohe
Forest Reserve Homesteads
24 Nov
0 1,000 2,000 Yards
0 0.5 1 Miles
N0 1 2 Km
magma continued to drain from the edifice; deflation did not
cease until the end of July (Fig. 2). On 21 August, the June 27th
flow was 9.4 km downslope from Pu‘u ‘Ō‘ō in a densely forested
area, where it encountered a series of large ground cracks
parallel to the rift zone. Lava flowed into the crack system and
advanced within it for 1.3 km, with the inferred location of the
flow front indicated by the downrift extent of small plumes of
condensed steam in the forest (Fig. 3B).The flow emerged
from the crack system 11.4 km downslope from Pu‘u ‘Ō‘ō on
24 August but repeated its disappearing act—entering a
crack and then emerging downslope days later—three more
times. Lava cleared the region of heavily cracked ground on
6 September at a point 13.3 km from Pu‘u ‘Ō‘ō, within a few
kilometers of the rural Kaohe Homesteads subdivision above
the town of Pāhoa (Fig. 1).
Over the succeeding weeks, the flow skirted the northwest
margin of Kaohe Homesteads, stalled in late September,
resumed its advance at the end of September, and, in mid-
October, stalled again ~1 km from the uppermost road of Pāhoa
(Fig. 1).The flow began advancing again on 22 October and
crossed the road on 25 October (Fig. 3C) before passing through
a cemetery and across private land (Fig. 3D), winding its way
between several residences that homeowners protected with
hastily constructed berms of soil and cinder. By 30 October, the
flow was within ~150 m of Pāhoa’s main street (Figs. 1 and 3E),
where it stalled, widening slightly without advancing over the
ensuing days.This widening damaged the Pāhoa solid waste
transfer station and, on 10 November, claimed a residence
upslope of the flow front—the only dwelling to be destroyed
during the 2014–2015 Pāhoa lava flow crisis.
The events of late September to early November established
a pattern that was to recur several times during the months that
followed: the lava flow front advanced, stalled, and widened, and
1 December 2014
Leilani Figure 4. Map distributed to the public on 1 Dec.
Estates 2014, showing June 27th lava flow on 24 Nov. 2014
(pink), and expansion as of 1 Dec. 2014 (red). Blue
lines are calculated paths of steepest descent. Black
lines are roads.
130
Flow on 1 December, 11:30 AM
Flow on 24 November, 12:00 PM
Steepest-descent path
then became inactive due to fluctuating supply of lava from the GSA TODAY | www.geosociety.org/gsatoday
source vent and breakdowns in the lava tube. Upslope breakouts
then formed a new lobe that advanced alongside the previous
one (Fig. 1). In late January 2015, one of these lobes was
within ~500 m of Highway 130, which links Pāhoa and nearby
communities to the rest of the island (Fig. 3E), but this lobe also
stalled and widened. New breakouts near Pu‘u ‘Ō‘ō in mid-
March robbed the downslope flow field of its supply of lava, and
flows near Pāhoa became inactive, thus ending the crisis. Since
then, lava has not advanced beyond ~9 km from Pu‘u ‘Ō‘ō.
JUNE 27TH LAVA FLOW HAZARDS ASSESSMENT,
MITIGATION, AND IMPACT
The response to the 2014–2015 Pāhoa lava flow crisis by the
public, businesses, and federal, state, and county agencies was
as complex as the June 27th flow itself.The Hawaiian Volcano
Observatory (HVO) tracked the lava flow by helicopter
overflights, ground-based mapping, and satellite imagery,
working closely with Hawai‘i County Civil Defense (HCCD) to
map flow progress. Observations were more frequent as the flow
neared homes, involving a continuous presence on the ground
during the height of the crisis. HVO and HCCD shared data on
flow activity and issued frequent updates, maps, and imagery via
the Internet and media outlets. HCCD updates played on the
radio, and an information and command center was opened in
Pāhoa while active lava was near the town.
At the direction of the mayor, the County of Hawai‘i
organized a community meeting in Pāhoa on 27 August 2014
—two days after HVO’s first press release and 10 days before
the mayor would issue an emergency declaration. For the next
several months, these community meetings were at least a
weekly occurrence, with attendance at some meetings exceeding
600 people (Fig. 3F). Overview presentations by HVO, the
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