Drones capture massive earth changes after Kaikoura Earthquake

Drones capture massive earth changes after Kaikoura Earthquake

GNS scientists made field observations of Kekerengu Fault rupture following the Kaikoura Earthquake and the fault scarp and uplifted coastal platform at Waipapa Bay above the Papatea Fault.

The Kekerengu Fault is one of the several faults that ruptured during the Kaikoura Earthquake of November 13, 2016.

Initial surveys show the length of the onland surface rupture to be approximately 30 km (18.6 miles) and a maximum of about 10 m (32.8 feet) horizontal and 2 m (6.5 feet) vertical displacement.

Average movement of the Kekerengu Fault has been calculated to be 20 to 25 m (65 to 85 feet) per 1 000 years.

Video courtesy GNS Science

The rocks seen on the drone video below have all been pushed up out of the sea by about 6 m (19.7 feet). The uplift along the fault has formed a vertical barrier and created a small lagoon.

A ridge of beach gravels marks the line of the fault. The road and railway have also been dislocated.

Video courtesy GNS Science

Video courtesy GNS Science

According to the USGS, the November 13, 2016 M7.8 earthquake in North Canterbury, New Zealand, occurred as the result of shallow oblique-reverse faulting on or near the boundary between the Pacific and Australia plates in South Island, New Zealand. At the location of this earthquake, the Pacific plate moves to the west-southwest with respect to the Australia plate at a rate of approximately 40 mm (1.57 inches) per year.

The epicenter was about 30 - 45 km (18.6 - 30 miles) south-southeast of the main surface expression of the plate boundary in the region—the Hope Fault, part of the Marlborough Fault system that connects a subduction zone (the Hikurangi Trough) to the primary plate boundary in the South Island—the Alpine Fault.

The plate boundary in the region of the earthquake is complex, involving a transition from subduction along the Hikurangi Trough to the east of the North Island, to transform faulting through the South Island. The shallow crustal region to the southeast of the Hope fault primarily involves thin-skinned shortening and fold and thrust belt tectonics. The size, depth (~25 km) and faulting orientation of the November 13 event suggest a larger, subduction-related structure, though the subduction zone interface is not thought to extend this far to the south. The complexity of the event, involving a main energy release delayed by about 40 s, combined with an early aftershock distribution extending about 150 km (93.2 miles) to the north-northeast of the mainshock, suggests the potential for triggered slip on the Pacific:Australia subduction zone interface.

While commonly plotted as points on maps, earthquakes of this size are more appropriately described as slip over a larger fault area. Reverse-faulting events of the size of the November 13, 2016 earthquake are typically about 120 x 50 km / 74.5 x 31 miles (length x width). Modeling of this event implies slip occurred over an area about 200 x 60 km / 124 x 37 miles in size. Over the 9 hours following the M7.8 mainshock, 25 aftershocks have occurred, ranging in size from M4.5 to M6.5 and extending from the region of the mainshock epicenter to about 160 km (99 miles) to the northeast.

The Pacific-Australia plate boundary in northern South Island has a history of large earthquakes both along the plate boundary proper and distributed around the plate boundary internal to the Australia and Pacific plates.

The Kaikoura Earthquake is the largest event in the region since an M7.3 earthquake 100 km (62 miles) to the northwest in June 1929.

The June 1929 earthquake occurred just 3 months after the March 1929 Arthur’s Pass strike-slip earthquake, 90 km (56 miles) to the west-southwest of the November 13th event.

The November 13, 2016 event is also about 100 km (62 miles) to the north of Christchurch, which was severely damaged by a series of large earthquakes in 2010-2015, including a M7.0 to the west of Christchurch in September 2010, and a M6.1 directly beneath the city in February 2011.

Featured image credit: GNS Science.

Comments

Hazel 15 days ago

unfortunately the world appears to be b dumbing down to a scary level as birth control is the elephant in the room never spoken of and more and more resources will be required if it is not addressed soon .Some of the people who have made their way into our own country bel;ieve in fixed forced marriage and that males are the head of the family sort of stuff we our selves have l;ong since discarded .I a woman I know does not even received her own money she works for but it goes to her huisbands bank account and she asks for spending money .This sort of behaviour is dark age stuff .Not to mention the woman I work with who after her husband crashed the car gave her pet rabbit away as she was told by him the rabbit bought him bad luck .See what we are dealing with and our government does not speak up denounce the over breeding of other nations or about women s rights or denouncing old tired religions for what they were so watch this space ,the pope will ask catholic s to carry on over breeding but has no answers as to how they will feed their young as we see they flock out of over populated countries hoping for a better life when it was there in front of them all the time .Birth control lets pay poorer people to stop at two or one child then we may have a chance but otherwise the amount of people will bring the planet to its knees .when our so called leaders are money men with not the most in Telligent of minds and are heel bent on making more and more money and building bigger and bigger house cars ect we are doomed as a species .

john paily 15 days ago

We are on the edge. For years, I have been calling attention of the leaders and the public as a whole to the fact that by exponentially increasing the heat of the environment we are stressing earth’s environment and its inner core. I have predicted increased forest fire; wind bound destruction, followed by flash floods/snows, earth quakes and volcanic eruptions. The two back to back 7 and above earth quakes in the last one week speaks of winding stress earth is experiencing. There is a Principle Design on which earth functions to sustain herself. It is time we awaken to it and lean to live in peace with her -https://www.scribd.com/document/322252992/Two-Critical-Dangers-to-Which-Earth-and-Humanity-is-Evolving

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