Orange Earthquake alert in Tanzania

On 7/17/2007 2:10:04 PM UTC an earthquake of magnitude 5.9 has struck the moderately populated region of Tanzania in Tanzania.

Humanitarian Impact
Population vulnerability
Tsunami probability
Landslide probability
Nuclear radiation probability

Whether international humanitarian aid is needed must be decided by an expert. However, the following automatically calculated elements can help. This earthquake has potentially a medium humanitarian impact and the affected region has medium vulnerability to natural disasters.

Explanation of alert calculation:
The impact model combines magnitude (M), population within 100km (P) and vulnerability ECHO average score (V) using the formula:
alertscore = max(M-4.5,0) * log10(max(P / 80000,0))^ 0.5 * max(V,0.5) ^ 1.5 / 3
The weighted product of magnitude, population and vulnerability (1.88) gives an alertscore of 1.14720587538654
Then alert is Red if alertscore>2, Orange if alertscore>1 and Green if alertscore<=1.

About the data

Source: European-Mediterranean Seismological Centre (EMSC)

Magnitude: definition

Potentially affected People

The population in the area of this earthquake if 8 people/km².

The earthquake occurred at 16h local time. At this time a day, more people are at work and therefore more vulnerable to collapsing office buildings. During traffic hours, people can be affected by collapsing bridges and other road infrastructure.

About the data

Population data: derived from the LandScan 2002 dataset provided by Oak Ridge National Laboratory, which disaggregated census data into pixels of ~1km² (or 30 arc seconds).

Damage

The affected region has low level of urban area (0%) and a high level of cultivated area (31.8%). In urban areas more damage can be expected than in cultivated or natural areas.

Radius (km)	urban areas	cultivated areas	other
200	0.08%	31.85%	68.06%
100	0%	22.16%	77.83%
50	0%	23.05%	76.94%
10	0%	18.95%	81.04%

In general, earthquakes of magnitude 5 to 6  cause, at most, slight damage to well-designed buildings, but can cause major damage to poorly constructed buildings over small regions.

For more information on the intensity of the earthquake around the epicentre, please refer to the USGS ShakeMap product (http://earthquake.usgs.gov/shakemap/global/shake/index.html)

About the data

Land use data from GLC2000. This data is specific to this earthquake.

This damage assessment is based on the average damage of earthquakes over a 100 year period as compiled by USGS. The information is not specific to this earthquake.

Resilience and Vulnerability

ECHO Intervention Priority Ranking for Tanzania
Overall situation
Human Development
Human Poverty
Exposure to Major Disasters
Natural Disasters
Conflicts
Humanitarian effects of population movement
Refugees
Internally Displaced People
Health and Nutrition
Undernourishment
Mortality rates
Donor contributions
Official Development assistance
Source ECHO Key: Bad - Medium - Good - No data

Resilience is the capacity of the population to cope with a hazard. Since much of investments in earthquake preparedness and available funds for quick response is related to household income, the GDP per capita can be used as a rough indicator of resilience.

Tanzania has a GDP per capita of 188 PPP$ (Parity Purchasing Power Dollar, about 1 Euro) and is therefore part of the low level income countries. Therefore, the earthquake happened in an area of low resilience.

Based on the combination of 9 indicators, ECHO attributes Tanzania a medium vulnerability.

About the data

Exposure

Both conditions for survival and conditions for delivering aid strongly depend on the current weather and temperature. The following graphs show the current and forecast weather.
Current weather conditions and forecasts at earthquake location (lat: -2.57 - long: 36.31)

More detailed observations at closest weather station (Arusha): WeatherByWeb - NOAA

About the data

Source: www.calle.com/world. The data is not very reliable, but it gives an indication for remote regions where more detailed information is not available. The data is interpolated for the given latitude and longitude from the closest airport weather stations.

Secondary effects

Probability of secondary effects:

• Landslides: The maximum slope in the area of the earthquake is 48.971% and the maximum altitude is 4217 m. Since this is a medium slope, the risk of earthquake induced landslides is medium. Note, however, that the slope data is not reliable on a local scale, while landslides depend very much on local topography, soil and meteorological conditions.
• Nuclear power plants: There are no nuclear facilities nearby the epicenter.
• Tsunami: based on magnitude alone, there is a unknown probability of a tsunami. However, this probability must be confirmed by oceanographic measurements or observations. Please refer to NOAA's tsunami alert system for information on tsunamis in the Pacific Ocean: http://tsunami.gov/. In case of a tsunami, the propagation is shown in the figure on top of this report.
  
   

About the data

Landslides: slope and altitude are derived from the gtopo30 dataset provided by USGS. The thresholds used for landslide related slope classes are: 0-30% - low risk (green), 30-60% medium risk (orange), 60-100% high risk (red).

Nuclear radiation: the distance to nuclear installations is evaluated based on a 1999 UN dataset containing the location of nuclear plants in the world. If plants are near and the earthquake magnitude is above 6.5, the alert is set to orange. Note that the location of plants is approximate with errors of up to 100km.

Tsunami: The JRC Tsunami model (http://tsunami.jrc.it/model) can be used solely to have a first estimate of the Tsunami wave propagation time. It does not predict predict the occurrence, the initial or final height of the wave, its run-up or the inundation depth.

Description

The earthquake happened in Tanzania, 155km from the city of Nairobi. The nearest populated places are Ketumbaine (19km).

It is a mountainous region with a maximum altitude of 4217 m.

About the data

Maps and description of location are based on Global Discovery data, provided by Europa Technology. The dataset is based on VMAP0 and is at scale 1:1.000.000.

Getting there and away

The nearest civilian airport (Arusha) is at 95km from the epicenter. See the map for more details.

The estimated geographical coordinates of the earthquake are: 2.57 South and 36.31 East.

Dynamic Maps

Mapping material available on the DMA for Tanzania:

• Interactive Country map: https://dmaweb2.jrc.it/services/dmaexplorer/?Country=Tanzania
• Interactive Event map: click on maps below

image area: approx. 130x90km2 image area: approx. 65x45km2

Legend of symbols in this page: