Papadopoulos-Imamura tsunami intensity scale Open new window

The proposed tsunami intensity scale by Papadopoulos and Imamura (2001) incorporates twelve divisions and is consistent with the several twelve-grade seismic intensity scales established and extensively used in Europe and North America in about the last 100 years. The new scale is arranged according to the effects on humans; the effects on objects, including vessels of variable size, and on nature; and damage to buildings. Maramai et al. (2014) specifies that this intensity scale has been calibrated to modern coastal environments, therefore does not provide accurate information when evaluating historical events ⁠.

	Descripción
	Descripción
Intensity	Effects on humans	Effects on objects, including vessels of variable size, and on nature	Damage to buildings
I. Not felt	Not felt even under the most favorable circumstances.	No effect.	No damage.
II. Scarcely felt	Felt by few people onboard small vessels. Not observed on the coast./p>	No effect.	No damage.
III. Weak	Felt by most people onboard small vessels. Observed by few people on the coast.	No effect.	No damage.
IV. Largely observed	Felt by all onboard small vessels and by few people onboard large vessels. Observed by most people on the coast.	Few small vessels move slightly onshore.	No damage.
V. Strong	Felt by all onboard large vessels and observed by all on the coast. PFew people are frightened and run to higher ground.	Many small vessels move strongly onshore, few of them crash into each other or overturn. Traces of sand layer are left behind on ground with favorable conditions. Limited flooding of cultivated land.	Limited flooding of outdoor facilities (e.g., gardens) of near-shore structures.
VI. Slightly damaging	Many people are frightened and run to higher ground.	Most small vessels move violently onshore, crash strongly into each other, or overturn.	Damage and flooding in a few wooden structures. Most masonry buildings withstand.
VII. Damaging	Most people are frightened and try to run to higher ground.	Many small vessels damaged. Few large vessels oscillate violently. Sand layer and accumulations of pebbles are left behind. Few aquaculture rafts washed away.	Many wooden structures damaged, few are demolished or washed away. Damage of grade 1 and flooding in a few masonry buildings.
VIII. Heavily damaging	All people escape to higher ground, a few are washed away.	Most of the small vessels are damaged, many are washed away. Few large vessels are moved ashore or crash into each other. Big objects are drifted away. Erosion and littering in the beach. Extensive flooding. Slight damage in tsunami control forest, stop drifts. Many aquaculture rafts washed away, few partially damaged.	Most wooden structures are washed away or demolished. Damage of grade 2 in a few masonry buildings. Most RC buildings sustain damage, in a few damage of grade 1 and flooding is observed.
IX. Destructive	Many people are washed away.	Most small vessels are destroyed or washed away. Many large vessels are moved violently ashore, few are destroyed. Extensive erosion and littering of the beach. Local ground subsidence. Partial destruction in tsunami control forest, stop drifts. Most aquaculture rafts washed away, many partially damaged.	Damage of grade 3 in many masonry buildings, few RC buildings suffer from damage grade 2.
X. Very destructive	General panic. Most people are washed away.	Most large vessels are moved violently ashore, many are destroyed or collide with buildings. Small boulders from the sea bottom are moved inland. Cars overturned and drifted. Oil spills, fires start. Extensive ground subsidence.	Damage of grade 4 in many masonry buildings, few RC buildings suffer from damage grade 3. Artificial embankments collapse, port water breaks damaged.
XI. Devastating		Lifelines interrupted. Extensive fires. Water backwash drifts cars and other objects in the sea. Big boulders from the sea bottom are moved inland.	Damage of grade 5 in many masonry buildings. Few RC buildings suffer from damage grade 4, many suffer from damage grade 3.
XII. Completely devastating			Practically all masonry buildings demolished. Most RC buildings suffer from at least damage grade 3.

Reference: Papadopoulos, G. A., & Imamura, F. (2001, August). A proposal for a new tsunami intensity scale. In ITS 2001 proceedings (Vol. 5, pp. 569-577).

Classification of damage to building

Although the classification of damage to buildings due to earthquakes is well defined (e.g. Coburn & Spence, 1992) such a classification is not still available for damage to buildings due to tsunamis. Therefore, only a gross classification is used in association to the tsunami intensity scale:

Grade 1: Slight damage
Grade 2: Moderate damage
Grade 3: Heavy damage
Grade 4: Destruction
Grade 5: Total damage

Source: The New Tsunami Intensity Scale. NEAMTIC, IOC/UNESCO. (a new window will open)