E
EARTHQUAKE DISTURBANCES
Islay D. Marsden
1
, Deirdre E. Hart
2
, Catherine M. Reid
3
and Christopher Gomez
2
1
School of Biological Sciences, University of Canterbury,
Christchurch, New Zealand
2
Department of Geography, University of Canterbury,
Christchurch, New Zealand
3
Geological Sciences, University of Canterbury,
Christchurch, New Zealand
Definition
Earthquake disturbances result from seismic activity, such
as shaking and ground deformation, generated naturally
by the rupture of geological faults, or volcanic activity.
Human activities such as drilling, mine blasts, and nuclear
tests may also simulate seismic disturbances. Direct disturbances generated by earthquakes are usually near field;
however, tsunamis may be associated with near- or
far-field earthquakes, causing significant effects.
Introduction
One of the earliest reports on the effects of earthquakes on
marine communities was from March 20, 1835, when
HMS Beagle visited Santa Maria Island, Chile, following
the M w 8–8.5 Concepción earthquake. Darwin (1846)
summarized the effects of up to 3 m coseismic uplift,
reporting dead and gaping mussels on a nearby rocky flat.
Similarly, an earthquake around 400 years ago lifted
Kaikoura Peninsula, New Zealand, up to 2 m vertically,
stranding the once-productive intertidal lagoons permanently above sea level and altering the food resource available to Māori (McFadgen, 1987). Since earthquakes and
their associated tsunami and mass movement events are
natural disturbances, there is widespread belief that estuarine communities are largely resilient to their effects over
medium to long time scales. In the twenty-first century,
however, earthquake events intersecting heavily modified
landscapes, such as the March 2011 Great East Japan or
Tōhoku M w 9.0 earthquake and tsunami, have the potential to produce profound future effects in estuaries.
The effects of earthquake events can be especially pronounced when tsunami inundate coastal lowlands,
destroying built environments and smothering coastal
and fluvial ecosystems with contaminated debris, or when
large volumes of pollutants such as fine sediments, trace
metals, and wastewater are released by liquefaction and
mass movement into estuarine catchments. The 2011
Tōhoku disaster adversely affected hundreds of kilometers
of coastal environments, including estuaries, when tsunami waves swept up to 3 km overland and were
conducted 3 km farther along river channels (Gomez et al.,
2012). In addition to the physical change wrought, damage to the Fukushima Daiichi Nuclear Power Complex
resulted in the accidental leak of radionuclides, making
fish and shellfish unsafe for human consumption. Initial
levels of radionuclides in the hen clam Pseudocardium
sachalinense reached 950 Ba/kg in Iwaki City, but levels
decreased in 2013 to below the regulatory limit of
32 Ba/kg. Similarly high levels were recorded for
bottom-dwelling fish, while pelagic fish recorded lower
levels (Toyofuku, 2013, “personal communication”).
Radioactive contamination has also been detected in the
coastal water table and sediments. This disaster has
prompted questions regarding the safety of the many
nuclear power plants along the tectonically active and
tsunami-receiving coasts of the world.
Estuarine coasts are spatially complex environments
around which to develop human settlement, often
resulting in built environments heavily reliant on bridge
systems and lacking inbuilt redundancy in their lifeline
networks (transport, water, gas, sewerage, and electricity).
Such infrastructure is especially vulnerable to earthquake
M.J. Kennish (ed.), Encyclopedia of Estuaries, DOI 10.1007/978-94-017-8801-4,
© Springer Science+Business Media Dordrecht 2016
EARTHQUAKE DISTURBANCES
Islay D. Marsden
1
, Deirdre E. Hart
2
, Catherine M. Reid
3
and Christopher Gomez
2
1
School of Biological Sciences, University of Canterbury,
Christchurch, New Zealand
2
Department of Geography, University of Canterbury,
Christchurch, New Zealand
3
Geological Sciences, University of Canterbury,
Christchurch, New Zealand
Definition
Earthquake disturbances result from seismic activity, such
as shaking and ground deformation, generated naturally
by the rupture of geological faults, or volcanic activity.
Human activities such as drilling, mine blasts, and nuclear
tests may also simulate seismic disturbances. Direct disturbances generated by earthquakes are usually near field;
however, tsunamis may be associated with near- or
far-field earthquakes, causing significant effects.
Introduction
One of the earliest reports on the effects of earthquakes on
marine communities was from March 20, 1835, when
HMS Beagle visited Santa Maria Island, Chile, following
the M w 8–8.5 Concepción earthquake. Darwin (1846)
summarized the effects of up to 3 m coseismic uplift,
reporting dead and gaping mussels on a nearby rocky flat.
Similarly, an earthquake around 400 years ago lifted
Kaikoura Peninsula, New Zealand, up to 2 m vertically,
stranding the once-productive intertidal lagoons permanently above sea level and altering the food resource available to Māori (McFadgen, 1987). Since earthquakes and
their associated tsunami and mass movement events are
natural disturbances, there is widespread belief that estuarine communities are largely resilient to their effects over
medium to long time scales. In the twenty-first century,
however, earthquake events intersecting heavily modified
landscapes, such as the March 2011 Great East Japan or
Tōhoku M w 9.0 earthquake and tsunami, have the potential to produce profound future effects in estuaries.
The effects of earthquake events can be especially pronounced when tsunami inundate coastal lowlands,
destroying built environments and smothering coastal
and fluvial ecosystems with contaminated debris, or when
large volumes of pollutants such as fine sediments, trace
metals, and wastewater are released by liquefaction and
mass movement into estuarine catchments. The 2011
Tōhoku disaster adversely affected hundreds of kilometers
of coastal environments, including estuaries, when tsunami waves swept up to 3 km overland and were
conducted 3 km farther along river channels (Gomez et al.,
2012). In addition to the physical change wrought, damage to the Fukushima Daiichi Nuclear Power Complex
resulted in the accidental leak of radionuclides, making
fish and shellfish unsafe for human consumption. Initial
levels of radionuclides in the hen clam Pseudocardium
sachalinense reached 950 Ba/kg in Iwaki City, but levels
decreased in 2013 to below the regulatory limit of
32 Ba/kg. Similarly high levels were recorded for
bottom-dwelling fish, while pelagic fish recorded lower
levels (Toyofuku, 2013, “personal communication”).
Radioactive contamination has also been detected in the
coastal water table and sediments. This disaster has
prompted questions regarding the safety of the many
nuclear power plants along the tectonically active and
tsunami-receiving coasts of the world.
Estuarine coasts are spatially complex environments
around which to develop human settlement, often
resulting in built environments heavily reliant on bridge
systems and lacking inbuilt redundancy in their lifeline
networks (transport, water, gas, sewerage, and electricity).
Such infrastructure is especially vulnerable to earthquake
M.J. Kennish (ed.), Encyclopedia of Estuaries, DOI 10.1007/978-94-017-8801-4,
© Springer Science+Business Media Dordrecht 2016