Natural Hazards: Causes and Effects - Disaster Management Center ...

Malnutrition — the condition of severe shortage of protein and calorie intake to such a degree
that wasting and shrinking of muscles occurs and performance of daily tasks is drastically
inhibited. Malnutrition is measured by several indicators, including upper arm circumference,
weight/height, weight/age ratios. These measurements are compared to a standard for a wellnourished
individual of the same age.
Mass care — provision of help, usually through public feeding centers where portions of a
disaster-stricken population are provided with at least one balanced meal per day. Mass care
involves the orderly feeding to families of a predetermined quantity and type of food matched,
as closely as possible, to the particular preferences of the region or country in question.
Mass wasting — a general term for the dislodging and downslope transport of soil and rock
material under the direct application of gravitational body stresses.
Medical self-help — training programs to help people prepare for survival in time of disaster
when coventionally trained medical help is not available or accessible.
Mercalli scale — a scale for rating earthquake intensity as humanly perceived, rated numerically
from “I — Not felt except by a very few,” to “XII — Damage total.” Also is called a modified
Mercalli scale or MM scale when used in North America.
Meteorology — the science concerned with the atmosphere and related phenomena.
Meteorologists observe the atmosphere, temperature, winds, density, clouds, and precipitation,
and analyze its observed structure and evolution in terms of the laws of physics.
Microclimate — the fine climate structure of the air space that extends from the surface of the
earth to a height at which the effects of the immediate characteristics of the underlying surface
can no longer be distinguished from the general local climate (mesoclimate or macroclimate).
Microearthquake — an earthquake having a magnitude of 2 or less on the Richter scale (see
Richter scale).
Microseismicity — small earthquake activity.
Microzonation — subdivision of a region into zones that have exposure to similar earthquakerelated
effects.
Mitigation — long-term measures taken to reduce the effects of disaster through alteration of the
physical environment, such as floodplain zoning and control, afforestation, land terracing, torrent
control, sand dune stabilization, and planting of shelterbelts or windbreaks.
MM scale — see Mercalli scale.
Monsoon — seasonally heavy rains and wind, particulary in the Indian Ocean and South Asian
areas. It can contain winds that change direction with the season, may cause severe damage,
and could require emergency response and disaster relief.