Turakirae Head

This area (seen in the photo) shows evidence of large scale uplift events through the presence of multiple marine terraces. These uplifts are caused by high magnitude shaking events that raise the land preserving past shorelines. Most of these earthquakes can be attributed to the Hikarangi Trough, a large subduction zone on the North Island, and other major faults that run through the area. The shoreline along the Turakirae Head consists of many marine terraces formed during the Holocene. The most recent marine terrace was caused by the Wyroba earthquake in 1855 with a Richter scale magnitude of 8.2, which raised the land 1 to 6 meters. The abandoned marine terraces form an anticline or convex fold in the ground. Many geologists have worked to date these terraces in order to help map a pattern of earthquake reoccurrence. They use various dating techniques, such as radiocarbon dating. Since radiocarbon dating can only date things up to 50,000 years of age, cosmogenic radionucleotide dating (CNR) is used to date cobbles found on very old high terraces. If a pattern of reoccurrence is developed, it could help to predict future earthquakes potentially saving the lives of many people. The photograph displays the multiple marine terraces leading up to the oldest ones. The older terraces can be identified by their fragmentation, which is caused by the years of erosion.