Amy's Postcards

Terraces can be seen all over New Zealand along with other parts of the world. Marine terraces can be seen on the North Island, New Zealand along the shore in this photo due to uplift events as a result of subduction occurring. The most recent event was in 1855, the Wairarapa earthquake which had an 8.2 magnitude. These marine terraces may have occurred during the last 10,000 years (Holocene). Marine terraces are wave-cut platforms that are ancient shore lines. They usually form as a result of waves that hit against the cliff and corrosion occurs. At these sea terraces, earlier sea levels can indicate reoccurrence intervals if dated. Older sea terraces are often more fragmented due to erosion processes. The terraces when standing at them are often clear cut; you are on a flat surface. Then you go up a few feet (slope upwards) and there is another flat surface, this indicates one of the steps up. Often scientists date shells and human artifacts (that may still be preserved where uplift occurred) to date back occurrence.