Hotspots

Definition

Hotspots are volcanic regions thought to be fed by underlying mantle that is anomalously hot compared to surrounding mantle. Unlike volcanism that occurs at plate boundaries, hotspots can create volcanoes in the middle of tectonic plates, leading to the formation of island chains and other volcanic features as the plate moves over a stationary hotspot.

5 Must Know Facts For Your Next Test

1. Hotspots are not limited to tectonic plate boundaries and can occur anywhere within a tectonic plate, which makes them unique compared to other volcanic activity.
2. The Hawaiian Islands are one of the most well-known examples of hotspot volcanism, formed as the Pacific Plate moves over a stationary hotspot.
3. As tectonic plates move over hotspots, they can create chains of islands or seamounts, where older volcanoes become extinct while new ones form.
4. The age of volcanic islands in a hotspot chain increases with distance from the current location of the hotspot, helping to track plate movement.
5. Hotspots provide critical insight into the dynamics of the Earth's interior and help scientists understand mantle convection and plate tectonics.

Review Questions

• How do hotspots differ from traditional volcanic activity associated with plate boundaries?
  • Hotspots differ from traditional volcanic activity in that they can create volcanoes in the center of tectonic plates rather than at their boundaries. While plate boundary volcanism is driven by tectonic interactions such as subduction or rifting, hotspots are fueled by mantle plumes that provide a consistent source of heat and magma. This leads to unique volcanic formations that can arise away from tectonic plate margins.
• Discuss the formation of island chains like the Hawaiian Islands in relation to hotspots and tectonic plate movement.
  • Island chains such as the Hawaiian Islands form as tectonic plates move over a stationary hotspot. As the plate shifts, it carries the volcanic island created by the hotspot away from its source of magma. New volcanic islands emerge over the hotspot as it remains active, creating a linear chain where older islands progressively age and become inactive. This process helps illustrate the movement of tectonic plates over geological time.
• Evaluate the implications of hotspot volcanism on our understanding of Earth's geology and mantle dynamics.
  • Hotspot volcanism has significant implications for understanding Earth's geology and mantle dynamics by providing insights into mantle convection processes. The existence of hotspots suggests that there are variations in heat flow within the Earth’s interior, challenging the traditional view that all volcanism occurs at plate boundaries. Studying these regions allows geologists to better comprehend how mantle plumes influence surface geology and contribute to plate tectonics, enhancing our overall knowledge of planetary processes.

Related terms

Mantle Plume: A localized column of hot magma rising through the mantle, believed to be responsible for creating hotspots.

Volcanic Arc: A series of volcanoes formed at a convergent plate boundary, typically associated with subduction zones.

Seamount: An underwater mountain formed by volcanic activity, which can be a result of hotspot volcanism.