Earthquakes & Seismicity

The largest and most devastating earthquake to have hit Fiji Islands was the 1953 Suva Earthquake. It took place September 14, 1953 near Suva, Fiji on the main Island Viti Levu. The earthquake had an estimated magnitude of 6.8, it has triggered a coral reef platform to collapse and also a submarine landslide which in turn caused a tsunami. This event took down many stores and houses within the city. 

Fiji is seismically active which means they experiences many earthquakes weekly/monthly, most occur mainly on the edges of the plate and in the ocean. The ones that do occur inland tend to be of low/medium magnitude. Many times earthquakes also bring about a tsunami. Though it is very rare to see another earthquake of similar magnitude to the 1953 Suva Earthquake take place inland. Two studies of "magnitude-frequency relations" near Fiji have shown that earthquakes of magnitude 7 or higher are expected every 15-21 years. While earthquakes of magnitude 6.5 or higher are expected every 2.5-6 years.

The northern and western Viti Levu, northern Vanua Levu, the South Fiji Basin, and the Lau ridge are all areas that have shown signs of having no "seismic activity on all time and magnitude scale."

The "Fiji Telemetered Seismic Network" is a 19 station national seismic network of Fiji. It provides the bulk of data for their research program, which is used to predict future earthquakes in order to prepare for them accordingly.



Comments

Post a Comment

Popular posts from this blog

Tsunamis

Image
One of the biggest Tsunamis to have hit Fiji was in 1953 due to the 6.7 earthquake in Suva. The earthquake had caused a slip in the seabed of the harbor  area which brought about the tsunami in the Suva Peninsula. It dealt major damage to the wharf and caused 3 deaths in Suva, 12 were also reported as drowned in the Fiji Islands Koro and Kadavu. The main source of the tsunami was the result of a "60 million cubic meter submarine landslide at the head of the Suva Canyon". Usually earthquakes near Fiji are the cause of tsunamis, but they can also be caused by "a sudden motion of the ocean floor." This could be due to an underwater landslide or even a powerful volcanic eruption. Tsunamis are a big concern as most population is concentrated in low coastal areas.  One way to further help lower injuries and damages would be to setup a real-time monitoring system of seismic activity and tsunami education and research program to study causes and frequent locations. These co
Read more

Climate Change

Image
The Pacific region as a whole is suffering more and more from extreme weather due to climate change aside global warming. They are most definitely the ones who are most vulnerable to it but also contribute the least in terms of global emissions. The average temperatures have already increased about 34 degrees Fahrenheit and are still on the rise. This also causes "ocean acidification" which is continuously increasing further with global warming. This affects reef ecosystems which is an essential part of the communities livelihood. due to this coastal erosion is also being sped up as they act as the "first line of defense against storm surges and strong waves". Global warming is also bringing about a rise in sea level. For example in Tuvalu, the sea level has already increased by around 13.2 cm from 1993 to 2021 with an upwards trend of 4.7mm per year. These alongside storm surges and king tides accelerate coastal inundation which is further affecting their water sec
Read more

Coastal Erosion

Image
Oceans coasts have always been susceptible to coastal erosion and Fiji has a lot of these coasts. There are 2 main reasons as to why coastal erosion may occur, the first is through natural causes and events, the second is through human interference with coastal processes. In general, the beaches and shorelines of Fiji showcase a strong coastal stability. but there are many specific areas which suffer erosion. In Fiji most if not all of coastal erosion is not due to any natural factor but because of human influence. One such case is the erosion at Long Sandy Beach on the island of Matacawa Levu in the resort known as Long Sandy Beach. Jetties were built in order to extend the area of the resort. "This blocked the existing coastal longshore-drift and current direction". This in return led to the reversed circulation hitting the shore and causing the erosion. The jetties had altered and changed the coastal currents which led to erosion over a specific area of the beach. Another
Read more