At 19:53 UTC, Lorengau, Papua New Guinea was shaken by a 5.3 magnitude earthquake with a depth of 24.22 km. This tremor came four hours after Kokopo, Papua New Guinea experienced a magnitude 5.4 quake with a depth of 22 km. There have not been any injury reports at this time.
Papua New Guinea sits on the Australia-Pacific plate, which is 4000 km long and runs along the north side margin. The plate travels from the Sunda Trench to the Solomon Islands. The Australian plate meets the Pacific plate at 95 mm a year.
The trench’s seismic activity comes from subduction tectonics, therefore, earthquakes are common. There have been 13 earthquakes with a 7.5 magnitude or higher since 1900 and three magnitude 8.1 megathrust events due to this subduction zone over the past century. Furthermore, there is a hazard map for this area, due to the significant amount of seismic activity.
How a tremor impacts the ground varies. Hazard maps show the probability of seismic activity, based on experiences over the past 50 years and how often tremors have been felt, as well as the properties of the ground that the tremors’ waves have to travel through. The maps also show areas that have significant sized earthquakes.
By Jeanette Smith
Earthquakes, USGS: M5.4-121 km SSW of Kokopo, New Guinea
Earthquakes, USGS: Earthquake Hazards 101-The Basics
Featured Image and Top Image Courtesy of Taro Taylor’s Flickr Page – Creative Commons License