By David Jacobson, Temblor
Faults have shaped our globe and provided us with natural beauty we cherish. However, they are also extremely hazardous, especially for the hundreds of millions of people living close to faults capable of producing major earthquakes. Therefore, seeing where faults are can be important both for knowing your hazard, and understanding why natural features appear. Because of this, Temblor has recently added faults for approximately 50 countries, spanning Europe, the Middle East, Southeast Asia, Japan, Taiwan, and New Zealand. Additionally, California’s Alquist-Priolo fault zones have also been included.
Another reason why adding more faults in Temblor is important, is that earthquakes strike on faults, and large earthquakes strike on large faults. So, the addition of faults enables us to better localize and identify where large and damaging shocks could occur.
To showcase some of the areas we’ve added, lets take a tour of some large faults.
New Zealand’s Alpine Fault
The Alpine Fault extends for over 400 km across New Zealand’s South Island. Approximately 75% of slip between the Australian and Pacific plates is accommodated on the Alpine Fault, and large (M=7.8+) earthquakes can take place along it. Additionally, it not only helped form, but marks the western boundary of the Southern Alps.
Turkey’s North Anatolian Fault
The North Anatolian Fault is similar both in length and movement to California’s San Andreas Fault. It most recently ruptured in the 1999 Izmit and Duzce earthquakes, which registered M=7.6 and M=7.2 respectively. The Sea of Marmara near Istanbul is partially a product of the North Anatolian Fault pulling apart the Earth’s crust.
Myanmar’s Sagaing Fault
Running for 1200 km through Myanmar, the Sagaing Fault is a major structure in between the Indian and Sunda plates. This right-lateral strike-slip fault moves approximately 32-40mm/yr and poses a great threat to many urban areas including the capital city of Naypyidaw. In addition to this fault, Myanmar also experiences seismicity from the offshore Sunda megathrust.
What all these maps show is that our globe is heavily faulted and earthquakes occur very regularly. Using the Global Earthquake Activity Rate (GEAR) model, we can approximate the earthquake magnitude that is likely in your lifetime anywhere on earth. And, as can be seen in Temblor, most earthquake fall where they are expected.
While the faults added to Temblor provide additional resources, should any agency or organization wish to provide more updated maps, we will be sure to update our site as quickly as possible.
Sources
USGS
USGS World Energy Project
GNS Science New Zealand
MTA (Turkey Faults)
Nakata T, Imaizumi T (eds) (2002) Digital Active Fault Map of Japan. University of Tokyo Press Tokyo DVD and 66 pp.
TEM Database (Taiwan Faults)
Southeast Asia Fault-source Evaluation in 2016 (SAFE2016)
Bird et al., Bull. Seismol. Soc. Amer. (2015) (Global Earthquake Activity Rate model)
Aung, et. al., Sagaing Fault slip and deformation in Myanmar observed by continuous GPS measurements, GNSS Applications in Geodesy and Geodynamics, Volume 7, Issue 1, (2016), p. 56-63.