Science - 06.12.2019

RESEARCH ARTICLE SUMMARY

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VOLCANOLOGY

Cyclic lava effusion during the 2018 eruption

of Kīlauea Volcano

M. R. Patrick*, H. R. Dietterich, J. J. Lyons, A. K. Diefenbach, C. Parcheta, K. R. Anderson, A. Namiki,

I. Sumita, B. Shiro, J. P. Kauahikaua

INTRODUCTION:The 2018 flank eruption and

summit collapse of Kīlauea Volcano was one

of the largest and most destructive volcanic

events in Hawai‘i in the past 200 years. The

eruption occurred on the volcano’slowerEast

Rift Zone (ERZ), draining magma at a high

rate from the summit reservoir and trigger-

ing incremental collapse of the overlying cal-

dera floor. Lava flows erupted for 3 months,

destroying several residential subdivisions and

burying miles of roads. The eruption rate ex-

hibited cyclic behavior on multiple time scales,

resulting in repeated lava breakouts and over-

flows. Multidisciplinary observations provide

insight into the nature of these variations,

driving forces in the magmatic system, and

implications for hazard.

RATIONALE:Volumetric eruption rate is a pri-

mary control on the vigor and hazard of lava

flows, but the processes that control its tem-

poral variations are not well understood because

of limited observational data. We integrated

field observations, photos and video from time-

lapse cameras and unmanned aircraft systems,

seismic tremor, and infrasound to track the

time scales and magnitude of fluctuations in

eruption rate at the primary vent for the 2018

eruption on Kīlauea’sLERZ.Wecombined

these data with documentation of summit cal-

dera collapses to investigate the origins and

impacts of these fluctuations.

RESULTS:Cyclic variations in eruption rate

occurred on two disparate time scales. First,

short-term fluctuations (“pulses”)ineruption

vigor had periods of 5 to 10 min, but had no

major implications for lava flow hazard. Flow

rate in the lava channel was inversely related

to fountaining and outgassing intensity at the

vent. Second, long-term fluctuations (“surges”)

had periods of 1 to 2 days and began within

minutes of episodic caldera collapse events

at the summit, 40 km upslope. These surges

triggered overflows from the channel that

produced hazardous enlargement of the lava

flow field, which could be forecast several

hours in advance. We also show that seismic

tremor and infrasound were correlated with

lava flow eruption rates.

CONCLUSION:We conclude that the two types

of eruption rate cycles were controlled by

two distinct processes. Short-term pulses

were driven by changes in outgassing effi-

ciency of the lava at shallow depths. Long-

term surges in eruption rate were driven by

pressure transients induced by the summit

collapses and transmitted through the mag-

ma conduit over a distance of 40 km. The

pressure-driven surges in eruption rate dem-

onstrate that the episodic rhythm of summit

caldera collapse sequences may be imparted

on the accompanying

flank eruption. The surges

also help to constrain the

efficient hydraulic con-

nection between Kīlauea’s

summit magma system

and rift zones and dem-

onstrate that pressure communication over

distances of 40 km can occur on a time scale

of minutes. Seismic tremor and infrasound

may be effective proxies for lava flow erup-

tion rates, allowing for improved tracking of

lava flow hazards. Our multidisciplinary data

provide a clear link between eruption rate

fluctuations and their driving processes in

the magmatic system.▪

RESEARCH

Patricket al.,Science 366 , 1213 (2019) 6 December 2019 1of1

The list of author affiliations is available in the full article online.

*Corresponding author. Email: [email protected]

Cite this article as M. R. Patricket al.,Science 366 ,

eaay9070 (2019); DOI: 10.1126/science.aay9070

Eruption rate cycles at fissure 8:

Period:

1-2 days

5-10 min.

1) Pressure-driven “surges” triggered by summit caldera

collapses, 40 km upslope

C

D

0 10 20 km

N

Island of Hawai‘i

K ī lauea

caldera

(summit)

Leilani Estates

Lower East Rift

Zone lava flow field

(May-Sep 2018)

EastR

iftZo

ne

Fissure 8

B

So

ut

hw

es

tR

iftZ

on

e

2) “Pulses” due to shallow outgassing changes,

local to the vent

Roads

(gray lines)

Fissure 8 vent

Spillway

(30 m wide)

Houses in

Leilani Estates

A

Unmanned aircraft systems video

Continuous time-lapse imagery

2018 eruption of K ̄laueaı

Volcano, Hawai‘i.(A) Fissure 8

vent on 25 June 2018. (B) The

LERZ eruption drew magma

from the summit reservoir,

triggering collapses of the

caldera floor. White dotted

line indicates the boundary

between Kīlauea and Mauna

Loa. (C) Schematic of eruption

rate cycles at fissure 8.

(D) Eruption rates were

monitored with time-lapse

cameras and unmanned

aircraft systems, as well as

seismic tremor and infrasound.

CREDITS: USGS; UAS

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Read the full article

at http://dx.doi.

org/10.1126/

science.aay9070

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