Tectonic Plates and Boundaries

• The major tectonic plates include the Pacific, North American, South American, African, Eurasian, Indo-Australian, Antarctic, Nazca, Philippine, and Arabian plates.

Tectonic Plate Boundary Types

• Divergent boundaries occur where plates move apart, leading to mid-ocean ridges, rift valleys, and volcanic activity, exemplified by the Mid-Atlantic Ridge.
• Convergent boundaries involve plate collisions, resulting in mountain formation, subduction zones, and earthquakes, such as in the Himalayas and Japan.
• Transform boundaries are where plates slide past each other, causing earthquakes, such as the San Andreas Fault.

Geological Diagrams

• Describing a plate boundary diagram involves identifying the boundary type, crust types, geological events, real-world locations, and long-term effects.

Convection Currents in Plate Tectonics

• Convection currents in the Earth's mantle are driven by heated rock rising, cooling, and sinking, facilitating plate movement, particularly at seafloor spreading and subduction zones like the Mid-Atlantic Ridge.

Earthquakes

• Strike-slip earthquakes involve plates sliding past each other, such as along the San Andreas Fault, while mega-thrust earthquakes occur in subduction zones, like in Japan and Chile, and are more powerful, with potential to cause tsunamis.
• Liquefaction happens when saturated soil loses strength due to seismic shaking, causing buildings to sink or collapse, which is especially dangerous in coastal cities.
• P-waves are fast, travel through solids and liquids, and cause minimal damage, while S-waves are slower, travel only through solids, and are more destructive.
• Intraplate earthquakes occur away from plate boundaries, for example, the New Madrid Seismic Zone.
• Subsidence is the sinking of ground due to natural or human-induced causes, such as groundwater extraction, like in Jakarta, Indonesia, or mining.
• Government instability and lack of coordination in disaster response can delay aid distribution.
• Earthquake Early Warning Systems, such as Japan’s EEW and ShakeAlert in the U.S., prompt immediate actions like halting public transport, industrial operations, surgery, and elevators

Tsunamis

• Tsunamis are caused by underwater earthquakes, volcanic eruptions, or landslides, not tides, which are driven by the moon.
• Tsunamis result from seafloor displacement, waves spreading rapidly in deep water, and wave height increasing dramatically near the shore.
• Tsunamis are caused by seismic activity, while meteo-tsunamis are caused by atmospheric pressure changes and can occur in the Great Lakes.
• Boats are safer in the deep open ocean during a tsunami because waves are small there, but become massive near the shore.
• Early warning signs of a tsunami include rapid ocean withdrawal, unusual seismic activity, and a roaring ocean sound.
• Immediate action when a tsunami is possible includes moving to higher ground.
• Hawaii is prone to tsunamis due to its location in the Pacific Ring of Fire and frequent seismic activity in surrounding oceanic trenches.