Tsunamis

 

 

 

A tsunami is a very long-wavelength wave of water that is generated by sudden displacement of the seafloor or disruption of any body of standing water. Tsunami are sometimes called “seismic sea waves”, although they can be generated by mechanisms other than earthquakes.
Tsunami have also been called “tidal waves”, but this term should not be used because they are not in any way related to the tides of the Earth. Because tsunami occur suddenly, often without warning, they are extremely dangerous to coastal communities.

Tsunamis can be associated with earthquakes. Sometimes a large earthquake beneath the ocean floor will produce a tsunami, which is a series of large waves.

The rate at which a wave loses its energy is inversely related to its wavelength. Since a tsunami has a very large wavelength, it will lose little energy as it propagates. Thus, in very deep water, a tsunami will travel at high speeds with little loss of energy.

As a tsunami leaves the deep water of the open sea and arrives at the shallow waters near the coast, it undergoes a transformation. Since the velocity of the tsunami is also related to the water depth, as the depth of the water decreases, the velocity of the tsunami decreases. The change of total energy of the tsunami, however, remains constant.

Furthermore, the period of the wave remains the same, and thus more water is forced between the wave crests causing the height of the wave to increase. Because of this “shoaling” effect, a tsunami that was imperceptible in deep water may grow to have wave heights of several meters or more.

The main damage from tsunami comes from the destructive nature of the waves themselves. Secondary effects include the debris acting as projectiles which then run into other objects, erosion that can undermine the foundations of structures built along coastlines, and fires that result from disruption of gas and electrical lines. Tertiary effects include loss of crops and water and electrical systems which can lead to famine and disease.

 

 

 

Our APPSC Notes Courses

PDF Notes for Prelims Exam

Printed Notes for Prelims Exam

Mock Test Series for Prelims Exam

PDF Notes for Mains Exam

Printed Notes for Mains Exam

Mock Test Series for Mains Exam

Daily Mains Answer Writing Program

APPSCE Mains Exam

APPSCE Prelims Exam

Admit Card

Syllabus & Exam Pattern

Previous Year Papers

Eligibility Criteria

Results

Answer Key

Cut Off

Recommended Books

Exam Analysis

Posts under APPSC

Score Card

Apply Online

Selection Process

Exam Dates

Exam Highlights

Notifications

Vacancies

Exam Pattern

Prelims Syllabus

Mains Syllabus

Study Notes

Application Form

Expected Cut-Off

Salary & Benefits

Mock Tests

Preparation Tips

Study Plan

Combined Competitive Examination (APPSCCE)
Assistant Engineer (Civil)
Assistant Engineer (Electrical)
Junior Engineer (Civil)
Junior Engineer (Electrical/Mechanical/Electronics/Telecommunication/Computer Engineering)
Assistant Audit Officer (AAO)
Assistant Section Officer (ASO)
Senior Personal Assistant (SPA)
Research Officer (RO)
Law Officer cum Junior Draftsman
Assistant Conservator of Forest (ACF)
Range Forest Officer (RFO)
Horticulture Development Officer (HDO)
Agriculture Development Officer (ADO)
Veterinary Officer
General Duty Medical Officer (GDMO)
Junior Specialist (Allopathy/Dental)
Medical Physicist
Lady Medical Officer
Sub-Inspector (Civil/IRBN)
Sub-Inspector (Telecommunication & Radio Technician)
Assistant System Manager
Computer Programmer
Assistant Programmer
Assistant Director (Training)
Assistant Auditor
Section Officer (LDCE)
Field Investigator
Foreman (Department of Printing)
Principal (ITI)
Principal (Law College)
Lecturer (Government Polytechnic)
Lecturer (DIET)
Post Graduate Teacher (PGT)
Trained Graduate Teacher (TGT)
Teacher-cum-Librarian
Finance & Accounts Officer / Treasury Officer
Inspector (Legal Metrology & Consumer Affairs)
Assistant Engineer (Agri-Irrigation Department)
Assistant Director (Cottage Industries)
Language Officer (Assamese / Bodo / Bengali)
Exit mobile version