do earthquakes occur in areas without identified large faults?

The key words you use are "identified" and "large." As far as I know, earthquakes occur at fault lines, whether or not they have been identified or are large.

Since this is not my area of expertise, I searched Google under the key words "earthquakes faults" to get these possible sources:

http://www.tinynet.com/faults.html
http://hometown.aol.com/jillconway/quakes.html
http://earthquake.usgs.gov/learning/faq.php
http://www.earthquakecountry.info/roots/basics.html
http://www.gns.cri.nz/what/earthact/earthquakes/earthquakefaq.html

I hope this helps. Thanks for asking.

Earthquakes primarily occur along fault lines, which are fractures in the Earth's crust where rocks have moved past each other. Faults can range in size from small cracks to large-scale structures that extend for hundreds of miles.

However, it is important to note that not all fault lines have been identified or mapped. Earthquake-prone regions like California, Japan, and Nepal have well-known and extensively studied faults, but there are still areas around the world where fault lines are yet to be discovered.

Additionally, earthquakes can occur in areas without identified large faults. These seismic events can be caused by smaller, less well-defined faults called "secondary faults" or "fault networks." These faults may not have clearly defined surfaces but can still generate enough stress and displacement to trigger an earthquake.

Scientists use various techniques to find and identify faults, including geological surveys, satellite imaging, and ground-based monitoring equipment. They study the characteristics of the fault, such as its location, depth, and history of seismic activity, to better understand the earthquake potential of a particular area.

To determine if earthquakes occur in areas without identified large faults, you can consult geological studies, earthquake databases, or scientific publications that focus on seismic activity in different regions. By analyzing seismic data and studying the geological conditions, scientists can identify areas prone to earthquakes, even if the exact fault lines are not yet mapped or well-known.