Comparison of Explosive Volcanic Eruptions with Effusive Volcanic Eruptions

An Explosive Eruption

An Effusive Eruption

Extreme Explosive Eruption

Extreme Effusive Eruption


Pinatubo (1991)

Laki (1783)

Yellowstone (2.059 Ma)

Siberian Traps (250 Ma)

Primary magma type





Duration of longest eruptive phase

9 hours

8 days

a few hours to days

Duration of emissions

5 days

8 months

670,000+ years

Volume of eruptives (DRE)

5 km3

Bulk volume of pyroclastic fallout

4 km3

0.4 km3

Dominant type of mass flow


basaltic lava


basaltic lava

Bulk volume of mass flow

6 km3

15 km3

2,450 km3

3 million km3

Area of mass flow

400 km2

565 km2

15,500 km2

5 million km2

Caldera formed

2.5 km diameter


75 km long 45 km wide


Eruption columns to

35 km

13 km

SO2 emissions

17 Mt

122 Mt

7 Gt sulphur

H2O emissions

491-921 Mt

235 Mt

Chlorine emissions

3-16 Mt

15 Mt

Fluorine emissions

7 Mt

Bromine emissions

11-25 kt

Maximum regional SO2 concentrations

300 ppbm

1000 ppbm

Average effect on climate

up to -0.5oC for 3 years

up to -4oC for 6 years

+8oC warming low-latitude sea surface

Warming of lower stratosphere

+3oC within 5 months

Peak change in surface temperature


+3.3oC in NW Europe

-10oC for a few months

Northern continental winter temperature


Explosive eruptions are short-lived but form aerosols in the lower stratosphere that cool Earth. Extrusive eruptions last much longer, extruding much more magma, but inject little into the stratosphere. DRE is dense-rock equivalent. Data for Pinatubo from Self et al. (1996)), Scott et al. (1996)Gerlach et al. (1996)(Bureau et al., 2000) and (Robock, 2002); Laki from Thordarson and Self (2003); Yellowstone from Christiansen (2001)Lanphere et al. (2002)Jones et al. (2005) and (Segschneider et al., 2013); Siberian Traps from Reichow et al. (2009)Black et al. (2012), and Joachimski et al. (2012).

Posted on April 28th, 2021    © 2023 Peter L. Ward. All Rights Reserved