PAGER - M 5.9 - SAMOA ISLANDS REGION

Alert Version: 2Monday, October 19th, 2009 at 22:49:37 UTCLocation: 15.3° S, 172.2° WDepth: 10kmEvent Id: US2009MYB5Created: 17 hours, 10 minutes after earthquake.

Overall, the population in this region resides in structures that are vulnerable to earthquake shaking, though some resistant structures exist. A magnitude 6.9 earthquake 147 km South of this one struck Tonga on September 28, 2006 (UTC), with estimated population exposures of 223,000 at intensity IV and 3,000 at intensity III, with no reported fatalities.

Exposure Summary

Estimated Population Exposed to Earthquake Shaking

Est. Modified Mercalli Intensity	Est. Population Exposure	Perceived Shaking	Potential Structure Damage
Est. Modified Mercalli Intensity	Est. Population Exposure	Perceived Shaking	Resistant	Vulnerable
X	0	Extreme	V. Heavy	V. Heavy
IX	0	Violent	Heavy	V. Heavy
VIII	0	Severe	Moderate/Heavy	Heavy
VII	0	Very Strong	Moderate	Moderate/Heavy
VI	0	Strong	Light	Moderate
V	0	Moderate	V. Light	Light
IV	274k	Light	none	none
II-III	--*	Weak	none	none
I	--*	Not Felt	none	none

*Estimated exposure only includes population within calculated shake map area

Population Exposure
Population per ~1 sq. km. from LandScan

Selected Cities Exposed

MMI	City	Pop.
IV	Fasitoouta	2k
IV	Nofoalii	2k
IV	Leulumoega	1k
IV	Gataivai	1k
IV	Solosolo	1k
IV	Falefa	1k
IV	Tafuna	11k
IV	Leone	4k
III	Apia	40k
III	Vaitele	6k
III	Pago Pago	4k

Shaking Intensity

Full City Exposure List

MMI	City	Population
IV	Nofoalii	2k
IV	Leulumoega	1k
IV	Gataivai	1k
IV	Fasitoouta	2k
IV	Solosolo	1k
IV	Lufilufi	1k
IV	Falefa	1k
IV	Matavai	1k
IV	Lotofaga	1k
IV	Vaitogi	1k
IV	Vailoatai	1k
IV	Tafuna	11k
IV	Leone	4k
IV	Satapuala	1k
IV	Malie	2k
IV	Faleula	3k
IV	Afenga	2k
III	Faleniu	3k
III	Malaeimi	1k
III	Mapusagafou	2k
III	Safotu	1k
III	Siusega	2k
III	Apia	40k
III	Vaiusu	2k
III	Vaitele	6k
III	Aua	2k
III	Fagatogo	2k
III	Pago Pago	4k

Downloads

PAGER results are generally available on the Internet within 30 minutes of the earthquake’s occurrence. However, information on the extent of shaking will be uncertain in the minutes and hours following and earthquake and typically improves as additional sensor data and reported intensities are acquired and incorporated into models of the earthquake's source. Users of PAGER estimates should account for uncertainty and always seek the most current PAGER release for any earthquake.