212
12 The Context of Global Climate Change: Climate-Driven Demography
of sustainability, may not have been threatened by the loss of biota through erosion, earlier earthquakes and local and nationwide tsunamis will also have destroyed
archaeological evidence.
Roy Walters and James Goff [26] provide a clear summary of palaeo-tsunami
data dating back to about 6,300 years BP which provides some precise detail directly
relevant to our argument for cumulative loss of archaeological evidence through erosion (pp. 145–146). Noting that “The 1450 ‘event’ is most likely related to a number
of tsunamis generated by a cluster of large earthquakes in the 15th century”, they
comment that evidence from archaeological sites shows “almost ubiquitous signal of
inundation found throughout the country”. In the case of Palliser Bay, they note that
the tsunami of AD 1450 penetrated 3.5 km inland with “erosion of coasts for about
1.5 km landward”. Given such extreme erosion, the hope of recovering archaeological evidence for the ancient settlement described in the traditional accounts of Maui
the Navigator’s meeting with the chieftainess at Orokoroko (see Chapter 16) is negligible. This is especially so given Walter and Goff’s detailing of earlier tsunami with
a comparable nationwide impact. One in AD 200 (a hundred years after Maui’s visit)
was generated by the Taupo eruption and other tsunami with nationwide impact
occurred in AD 500, 950 and 1220. Though population levels before AD 1000 may
not have been close enough to ceilings of sustainability for these events to have
significant demographic impact, the cumulative erosion from these major tsunami
greatly reduces the chances of piecing together the early coastal settlement history
of New Zealand from archaeological evidence, as does the resculpting of landscapes
that Grant describes through climate-driven erosion of hillsides and valleys and the
creation of lakes through the accumulation of silt.
The seismically active character of New Zealand due to the interface between
the Australian and Pacific plates, evidence for recurrent clusters of earthquakes both
terrestrial and submarine, for tsunamis and for volcanic eruptions triggering landslides have clearly played a part in shaping the erosion history of New Zealand. An
inevitable loss of archaeological evidence reaching back to first settlement can sensibly be assumed. All such catastrophes must inevitably have impacted on the biota in
the short term at least. The earthquake cluster and major tsunami of AD 1450 will
have impacted on Maori food resources through the smothering of shellfish beds,
the destruction of forest and reduction of fish stocks and through damage to gardens
through salt inundations and the encroachment of sand. The cumulative destruction
of forest foods and fish stocks through cold and catastrophic tectonic and volcanic
events and a nationwide tsunami expand the picture of climate-driven demography we have been painting – reinforcing our demographic argument for starvation and conflict and drastically falling Maori populations in New Zealand after
AD 1400.
In his recent book, Hostile Shores: Catastrophic Events in Prehistoric New
Zealand and Their Impact on Maori Coastal Communities [29], Bruce McFadgen
argues for a significant loss of life for Maori in the tsunamis of c. AD 1450. He
correlates major loss of life with a loss of technological sophistication in adzemaking and in canoe-building in New Zealand caused, he suggests, by the drowning
12 The Context of Global Climate Change: Climate-Driven Demography
of sustainability, may not have been threatened by the loss of biota through erosion, earlier earthquakes and local and nationwide tsunamis will also have destroyed
archaeological evidence.
Roy Walters and James Goff [26] provide a clear summary of palaeo-tsunami
data dating back to about 6,300 years BP which provides some precise detail directly
relevant to our argument for cumulative loss of archaeological evidence through erosion (pp. 145–146). Noting that “The 1450 ‘event’ is most likely related to a number
of tsunamis generated by a cluster of large earthquakes in the 15th century”, they
comment that evidence from archaeological sites shows “almost ubiquitous signal of
inundation found throughout the country”. In the case of Palliser Bay, they note that
the tsunami of AD 1450 penetrated 3.5 km inland with “erosion of coasts for about
1.5 km landward”. Given such extreme erosion, the hope of recovering archaeological evidence for the ancient settlement described in the traditional accounts of Maui
the Navigator’s meeting with the chieftainess at Orokoroko (see Chapter 16) is negligible. This is especially so given Walter and Goff’s detailing of earlier tsunami with
a comparable nationwide impact. One in AD 200 (a hundred years after Maui’s visit)
was generated by the Taupo eruption and other tsunami with nationwide impact
occurred in AD 500, 950 and 1220. Though population levels before AD 1000 may
not have been close enough to ceilings of sustainability for these events to have
significant demographic impact, the cumulative erosion from these major tsunami
greatly reduces the chances of piecing together the early coastal settlement history
of New Zealand from archaeological evidence, as does the resculpting of landscapes
that Grant describes through climate-driven erosion of hillsides and valleys and the
creation of lakes through the accumulation of silt.
The seismically active character of New Zealand due to the interface between
the Australian and Pacific plates, evidence for recurrent clusters of earthquakes both
terrestrial and submarine, for tsunamis and for volcanic eruptions triggering landslides have clearly played a part in shaping the erosion history of New Zealand. An
inevitable loss of archaeological evidence reaching back to first settlement can sensibly be assumed. All such catastrophes must inevitably have impacted on the biota in
the short term at least. The earthquake cluster and major tsunami of AD 1450 will
have impacted on Maori food resources through the smothering of shellfish beds,
the destruction of forest and reduction of fish stocks and through damage to gardens
through salt inundations and the encroachment of sand. The cumulative destruction
of forest foods and fish stocks through cold and catastrophic tectonic and volcanic
events and a nationwide tsunami expand the picture of climate-driven demography we have been painting – reinforcing our demographic argument for starvation and conflict and drastically falling Maori populations in New Zealand after
AD 1400.
In his recent book, Hostile Shores: Catastrophic Events in Prehistoric New
Zealand and Their Impact on Maori Coastal Communities [29], Bruce McFadgen
argues for a significant loss of life for Maori in the tsunamis of c. AD 1450. He
correlates major loss of life with a loss of technological sophistication in adzemaking and in canoe-building in New Zealand caused, he suggests, by the drowning