Approximately 400,000 people face the risk of a tsunami disaster after the discovery of a 72 km fault line by scientists.
Hidden beneath the lush canopy of Vancouver Island in Canada, researchers have uncovered a new geological threat – a 72 km-long fault. This “tear” is named the XELF-Elk Lake Fault (XELF). The XELF fault runs through the Saanich Peninsula in Greater Victoria, Canada – the second-largest country in the world by area.
Following the discovery of this massive tear, geologists, mineralogists, earth scientists, and oceanographers from France, the United States, and Canada have jointly warned that the XELF fault could pose a significant tsunami risk, as reported by the National Post (Canada) on December 15.
The XELF fault has the potential to cause a strong earthquake, which could lead to a tsunami affecting hundreds of thousands of people, scientists warn. (Illustrative image).
The initial discovery of the fault was challenging due to dense forest cover, but extensive research methods such as shallow geophysical surveys, historical image analysis, and remote sensing helped scientists uncover this gigantic fault line.
“Evidence confirming the presence of the active XELF fault is the exposure of Quaternary sediments that are fractured and folded as we excavated the area. By using radiocarbon dating methods on organic material in the sediments, we were able to date these sediments, which date back approximately 14,000 years ago” – the scientists wrote in the journal Tectonics.
The research team also identified minerals in the rocks indicating changes in the magnetic field over time – a clear sign of the formation of rocks that are separated or fractured, further supporting the presence of a fault line.
Disaster Warning for Canada and the U.S. West Coast
According to the scientists’ research, the XELF fault runs from northwest to southeast and could be a normal fault, where rock masses move vertically in relation to one another.
Typically, faults occur in areas with unstable geological conditions. Thus, if an earthquake occurs along this fault line, it could trigger local tsunamis in the surrounding waters of Greater Victoria with catastrophic consequences for approximately 400,000 residents in the Greater Victoria area of Canada, potentially impacting cities along the U.S. West Coast, including Seattle, Bellingham, Olympia, and Tacoma, scientists warn.
Greater Victoria is located in British Columbia, Canada, at the southern tip of Vancouver Island.
Moreover, there are concerns that the XELF fault may be related to the Devils Mountain Fault in Washington State, which increases the risk for the United States.
A tsunami risk warning model indicates potential impacts on surrounding areas if a strong earthquake similar to those that occurred 2,300 to 4,700 years ago happens.
The most recent earthquake from this fault occurred several thousand years ago (between 2,300 and 4,700 years ago) with a magnitude ranging from 6.1 to 7.6. This event may have also triggered a tsunami in history. Currently, a collective of international scientists is still studying this ancient earthquake.
“Determining whether the XELF fault has caused recent large earthquakes is crucial for updating earthquake risk models in the region and enhancing earthquake response preparedness“, the researchers stated in the journal Tectonics.
Due to its proximity to urban areas, the potential impact of an earthquake of a similar magnitude to the ancient earthquake could be devastating today. The lead author emphasized the difficulty in predicting the timing of such an event but encouraged preparation and careful study of the “cutting” activity of the fault that bisects the Greater Victoria area.
The lead author Nicolas Harrichhausen (a postdoctoral researcher at the University of Grenoble Alpes in France) told the National Post: “At this point, we cannot clearly define what the hazards are. But one thing is certain: there will be risks that we need to consider. However, since we have only witnessed one earthquake in at least the past few thousand years, it is very difficult to calculate the level of risk.
We need more information, i.e., more research and funding, to better determine the slip rate of the XELF fault and the number of earthquakes that have occurred in the past. Only then can we use models to estimate the risks posed to the Greater Victoria area.”
