Scientists in Canada have evaluated novel satellite and lidar mapping data and found that an ancient fault could potentially generate a powerful earthquake exceeding magnitude 7.5 on the Richter scale.<\/p>\n
The researchers from the University of Victoria (UVic) believe that the 620-mile-long Tintina fault which stretches northwest across the Yukon Territory could be still active. <\/p>\n
Geologists had long believed the fault was dormant for at least 40 million years, a view now challenged by new findings from high-resolution topographic mapping conducted using satellites, airplanes, and drones.<\/p>\n
The group based their conclusions on a 80-mile-long section near Dawson City that exhibits clear signs of movement in the geologically recent past.<\/p>\n
\u201cThe expanding availability of high-resolution data prompted us to re-examine the fault, looking for evidence of prehistoric earthquakes in the landscape,\u201d Theron Finley, PhD, a surficial geologist and\u00a0lead author of the study, stated. <\/p>\n
Rare signs of activity<\/p>\n
The study suggests the fault has slipped multiple times over the past 2.6 million years, a span known as the Quaternary period. While some glacial\u00a0landforms<\/a> are displaced by up to 3,280 feet, others, believed to date back t about 132,000 years ago, are offset by 246 feet. <\/p>\n Additionally, certain landforms dating back 12,000 years remain unbroken by the fault, suggesting no major ruptures have occurred since then. According to Finley, the fault is steadily accumulating strain at a rate of up to 0.03 inches per year. This indicates it remains a potential source of future earthquakes<\/a>.<\/p>\n \u201cOver the past couple of decades there have been a few small earthquakes<\/a> of magnitude three to four detected along the Tintina fault, but nothing to suggest it is capable of large ruptures,\u201d Finley emphasized.<\/p>\n Canada\u2019s seismic hazard assessments rely on indigenous oral histories, written records, and modern seismic monitoring, which only span the past few centuries. However, large earthquakes can strike on active faults thousands of years apart. <\/p>\n Preventing future disasters<\/p>\n Detecting subtle fault scarps, which are long, narrow surface features that mark past ruptures and are often hidden beneath forest cover, should be a priority and can only be achieved through extremely precise mapping.<\/p>\n \u201cWe determined that future earthquakes on the Tintina fault could exceed magnitude 7.5,\u201d Finley said in a press release<\/a>. He believes the fault could be in a late seismic cycle stage, with a nearly 20-foot-long strain build-up over the past 12,000 years. <\/p>\n \u201cIf this were to be released, it would cause a significant earthquake,\u201d the scientist concluded, adding that an earthquake of such magnitude would severely shake Dawson City and threaten nearby highways and mines.<\/p>\n Currently, Canada\u2019s National Seismic Hazard Model does not list the Tintina fault as a discrete source of large earthquakes. That\u2019s however set to change, as the new data will be incorporated into future hazard models, informing building codes and emergency planning.<\/p>\n The findings will also be shared with local governments and emergency managers to improve earthquake readiness and ensure communities are better equipped to respond when a major seismic event occurs.<\/p>\n