Earthquakes can cause the ground to move in a variety of ways, including shaking, tilting, and uplift. The aftershocks that follow an earthquake can also cause the ground to move, but these movements are typically smaller than the main shock. In some cases, however, the aftershocks can be large enough to cause significant damage.
One of the challenges in studying earthquakes is measuring the ground motion that occurs during and after an event. Traditional seismic instruments can only measure ground motion at a single location, so they are not able to capture the full picture of how the ground is moving. To overcome this limitation, scientists have developed new techniques that use sub-daily GPS data to measure ground motion.
Sub-daily GPS data is collected by GPS receivers that are able to record their position at a rate of one or more times per second. This data can be used to measure ground motion with much greater precision than traditional seismic instruments. In addition, sub-daily GPS data can be collected from multiple locations, which allows scientists to create maps of how the ground is moving.
In a recent study, scientists used sub-daily GPS data to study the ground motion that occurred after the 2016 Kaikoura earthquake in New Zealand. The earthquake caused widespread damage, and the aftershocks continued for months. The scientists found that the aftershocks caused the ground to move in a variety of ways, including shaking, tilting, and uplift. The maps created from the sub-daily GPS data showed that the ground motion was most intense near the epicenter of the earthquake, but it was also felt at locations hundreds of kilometers away.
The study by scientists demonstrated the power of sub-daily GPS data for studying earthquakes. This technique can be used to measure ground motion with much greater precision than traditional seismic instruments, and it can also be used to create maps of how the ground is moving. This information can be used to understand the physics of earthquakes and to develop more accurate earthquake early warning systems.
In addition to studying earthquakes, sub-daily GPS data can also be used to study other types of ground deformation, such as volcanic activity, landslides, and subsidence. This technique is a powerful tool for understanding the dynamics of the Earth's surface.
