The eastern side of the North Island relies on rainfall from cold fronts, which causes irregular patterns including moisture deficiencies and extreme conditions of temperature (Garnier, 1958). Garnier (1958) has found that the mountain ranges have formed a climatic barrier separating the west and east and resulting in the different climates and geomorphology: the Tararua range; the Ruahine; the Kaimanawa; and the Ruakamara Mountains (Garnier, 1958).
The eastern north island, New Zealand, is the case study for this essay; it is going to discuss two mechanisms that influenced the geomorphology of the Eastern side of the North Island; plate tectonics and Quaternary climate changes. The dominant features that will be discussed are; hikurangi …show more content…
Its time span goes back 2.6 million years ago and due to the Holocene period can accordingly be called the Age of Man (Quaternary Period, 2014). During the quaternary period fluctuations of the climate caused glaciers to advance from the poles and retreat with each cycle, carving and moulding the land (National Geographic, 2014). Over the past 800,000 years the planet has formed cyclical patterns, with ice ages lasting around 100,000 years followed by warm periods lasting 10,000-15,000 years. The last ice age occurred 10,000 years ago and as the ice retreated, sea levels rose rapidly and the continents achieved their present day positions (National Geographic, 2014). As the ice sheet retreated it exposed the land to large basins and rivers, forming lakes we see …show more content…
The study found that about one quarter of down cutting was caused by tectonic uplift, while the majority of the remaining reasons for down cutting were due to stabilisation in the upper catchment of the Waipaoa. This study shows that the resulting terraces in the study area were influenced by both tectonic setting and the quaternary climate.
Figure 3 (Litchfield & Berryman, 2005, pg 295): Cross section of a fluvial terrace and relationship with loess and tephra sediments.
The fluvial terrace in figure 3 (above) used loess and tephra sediments to determine the age of the terrace. The sediment has formed through erosion during the LGM, which has caused fill and cut terraces throughout the study area (Litchfield & Berryman, 2005). Tectonic uplift processes have been found to have preserved the terraces in a study by Litchfield et al.