The key facts

  • Following the magnitude 7.5 earthquake of October 9, Panama has recorded 746 aftershocks.
  • Scientists are verifying reports of the sea receding, changes in water color, and the splitting of Isla Cañas.
  • Strengthening monitoring requires about 150 instruments, and an early warning system requires 700 sensors.

746 aftershocks after the earthquake

Panama has recorded 746 aftershocks following the magnitude 7.5 earthquake that occurred last week, local media report. According to Néstor Luque, director of the Institute of Geosciences at the University of Panama, according to theory and historical data, aftershocks from an earthquake of such magnitude can continue for one to two months. The hypocenter was located at a depth of less than 10 kilometers, and the energy being released continues to cause a readjustment of tectonic blocks. Seismic data show that the magnitude of the aftershocks is gradually decreasing.

Changes on the coast and the island

Researchers are examining reports of changes along Panama's Pacific coast, where residents observed exposed rocks and areas where, according to them, the sea receded. Luque explained that fault movements can cause coastal land to rise or subside, changing the shape of the surface. Geologists are surveying the affected areas to determine whether fault movements were the cause. Reports of changes in water color, including grayish hues, are also being studied: it is possible that groundwater came into contact with minerals released during the earthquake, but chemical analyses are needed to establish the cause. Residents of Isla Cañas in the province of Los Santos reported that the island apparently split apart after the earthquake; geologists will check whether the cracks reach the sea, which could indicate fault movement.

Related and unrelated tremors, monitoring needs

Luque added that earthquakes in the provinces of Chiriquí and Bocas del Toro are associated with separate fault systems and are not necessarily related to the October 9 tremor. According to the Institute of Geosciences' estimate, about 150 instruments will be needed to strengthen seismic monitoring, and 700 sensors for a nationwide early warning system.