Seafloor spreading

Definition

Seafloor spreading is the geological process through which new oceanic crust forms at mid-ocean ridges and slowly moves away from the ridge as tectonic plates diverge. This process is a key component of plate tectonics, which explains how the Earth's lithosphere is divided into large sections that move and interact, influencing geothermal activity and the distribution of geothermal resources.

5 Must Know Facts For Your Next Test

1. Seafloor spreading occurs at mid-ocean ridges, where magma rises to create new oceanic crust, contributing to the formation of features like rift valleys.
2. As new crust forms, it pushes older crust away from the ridge, causing the ocean floor to gradually expand and leading to an increase in ocean basin size.
3. This process is responsible for the symmetrical patterns of magnetic stripes found on either side of mid-ocean ridges, providing evidence for plate tectonics.
4. Seafloor spreading plays a critical role in the recycling of Earth's materials, contributing to the movement of tectonic plates and the associated geological phenomena like earthquakes and volcanic activity.
5. The heat generated during seafloor spreading contributes to hydrothermal vents, which are important for unique ecosystems and can also influence geothermal energy resources.

Review Questions

• How does seafloor spreading contribute to the movement of tectonic plates and what implications does this have for geothermal resources?
  • Seafloor spreading creates new oceanic crust at mid-ocean ridges as tectonic plates diverge. This movement leads to shifts in plate boundaries, resulting in volcanic activity and earthquakes, which can impact geothermal resources. The interaction between these plates can create areas with significant geothermal potential, making understanding this process essential for harnessing renewable energy from geothermal systems.
• Discuss the relationship between seafloor spreading and the formation of mid-ocean ridges, including how this process affects global oceanic circulation.
  • Seafloor spreading occurs at mid-ocean ridges where tectonic plates pull apart, allowing magma to rise and form new oceanic crust. This continuous creation of new material at ridges contributes to the uplift of underwater mountains and plays a crucial role in global oceanic circulation patterns. The changes in seafloor topography influence currents that help regulate climate and affect marine ecosystems.
• Evaluate the evidence supporting seafloor spreading as a mechanism for continental drift and its significance in understanding Earth's geological history.
  • Evidence for seafloor spreading includes symmetrical magnetic stripes on either side of mid-ocean ridges and age dating of ocean floor rocks. This supports the idea that continents drift over time as they are carried by moving tectonic plates. Understanding seafloor spreading is significant as it provides insights into Earth's geological history, explaining past continental configurations and predicting future movements, which is essential for assessing risks associated with natural hazards.

Related terms

Mid-ocean ridge: An underwater mountain range formed by plate tectonics, where new oceanic crust is created as magma rises to the surface.

Tectonic plates: Massive slabs of Earth's lithosphere that fit together like a jigsaw puzzle and move over the semi-fluid asthenosphere, leading to geological activity.

Geothermal gradient: The rate at which temperature increases with depth in the Earth, which can be influenced by processes such as seafloor spreading.