Final answer:
Iceland’s southern population density is higher due to its moderate climates, lesser volcanic activity, and more economic opportunities, including a developed infrastructure and access to services.
Step-by-step explanation:
The population density in Iceland is higher in the southern part of the country primarily due to moderate climates and greater economic opportunities.
Iceland's location on a geological hot-spot means that the north of the country is more prone to volcanic activity, making it less appealing for dense human settlement. Furthermore, geothermal energy production, which is a byproduct of this volcanic activity, is not a dominant economic driver that would attract a large population to those areas.
The southern part of Iceland, with its milder Type C climate and closer proximity to the capital city of Reykjavik, provides a more conducive environment for habitation and economic activity such as the fishing industry, which is not exclusive to this region but is a significant part of the national economy.
Lastly, while population density may be influenced by the availability of jobs in particular sectors like fishing, it's also important to consider other factors such as access to transportation, services, and other infrastructures which are more developed in the southern regions of the country.