2. What effects do tsunamis have on the coastal ecosystem? Discuss.
तटीय पारिस्थितिकी तंत्र पर सुनामी का क्या प्रभाव पड़ता है? चर्चा करें।
A tsunami is a wave, or series of waves, caused by the vertical displacement of a column of water. This can be generated by earthquakes below the sea floor and violent volcanic eruptions above it, landslides above or below water or meteorite impacts into the sea.
Effects of Tsunami
- Sea Floor Erosion:
- The base of a tsunami wave can change the topography of the sea floor. It erodes seafloor sediments and can devastate the benthic – sea bottom – ecosystems on the sea floor. These are usually invertebrates like crustaceans, worms and snails that burrow through sea floor sediments and mix them. Sometimes, huge chunks of the sea floor can ripped up. The March 2011 Tohoku, Japan, earthquake tsunami deposited the eroded sediments in other locations as huge seafloor sand dunes.
- Coral Reefs:
- Coral reefs are natural breakwaters for a tsunami wave as it moves towards the coastline. The December 2004 Indonesian earthquake tsunami devastated coral reefs around Indian Ocean coastlines.
- Intertidal environments:
- Sea grass beds, mangrove forests, coastal wetlands and their associated fish and animal life in the intertidal zone are particularly vulnerable to tsunamis. This is the part of a coast that is exposed to the air at low tide and is submerged at high tide.
- Species Invasion:
- Tsunamis can carry massive amounts of debris from one side of the ocean to another. A concrete block from Misawa, Japan took 15 months to cross the Pacific Ocean and crash into the Oregon coast. Algae and other organisms attached to this debris survived the ocean crossing. These can establish new communities in Oregon and potentially displace native species.
- Contamination of soil and water:
- The 2004 Tsunami led to Salivation of water bodies such as rivers, lakes, wells in many of the effected countries
Tsunami is a natural disaster and damage to Tsunami can be mitigated by healthy well maintained coral reefs, mangroves, sand dunes and other coastal systems such as peat swamp. World over efforts have been taken to reduce the loss of life by tsunami with investment in early warning systems.