Why is the plate tectonic theory accepted today over the continental drift theory
The plate tectonic theory is accepted today because it provides a more comprehensive explanation of the Earth's geological features and phenomena compared to the earlier continental drift theory. Here are a few reasons why the plate tectonic theory is preferred:
1. Perceptible mechanism: The plate tectonic theory is based on the concept of rigid lithospheric plates that move and interact with each other. This movement is driven by the convective flow of the underlying semi-fluid asthenosphere. These observable movements and interactions of plates provide a perceivable mechanism for explaining various geological phenomena such as earthquakes, mountain formation, and volcanic activity.
2. Evidence from multiple fields: Plate tectonics is supported by extensive evidence from various scientific disciplines, including geology, paleontology, geophysics, paleomagnetism, and marine geology. This multidisciplinary approach provides a robust framework for understanding Earth's geological history, evolution, and dynamics.
3. Seafloor spreading and magnetic anomalies: One of the key pieces of evidence supporting plate tectonics is the discovery of seafloor spreading. Scientists have found that new oceanic crust is formed at mid-oceanic ridges, where plates move apart, and this process continuously pushes the existing oceanic crust away from the ridge. Additionally, the measurement of magnetic properties of seafloor rocks has revealed striped patterns of magnetic anomalies parallel to the ridges, further confirming the continuously expanding nature of the seafloor.
4. Subduction zones and trenches: Plate tectonics explains the existence of deep ocean trenches and associated subduction zones. At these locations, one plate dives beneath another, usually an oceanic plate descending below a continental plate, leading to the creation of trenches and volcanic arcs. This phenomenon is well-documented and consistently observed across the globe, providing strong evidence for plate interactions.
5. Global distribution of earthquakes and volcanoes: Earthquakes and volcanic activities align with plate boundaries, such as transform faults, divergent boundaries, and convergent boundaries. The occurrence of these geological phenomenon in a systematic manner is best explained by the plate tectonic theory.
Overall, the plate tectonic theory offers a more encompassing framework that explains the dynamics of the Earth's lithosphere, and its ability to account for a wide range of geological features and processes has made it the accepted paradigm in modern geology.