How SASPe plans to save your life

The quakes have a sort of weak point – the science learned how to take advantage of it.

 

By Nelson Peñaherrera Castillo

 

 

SANTA MARÍA DE NIEVA, Peru – On November 28th, 2021, 5:52 PET (1052 GMT), a 7.5 magnitude quake shook Barranca District, Datem del Marañón Province, Loreto Department – it was mostly felt in the Peruvian Northern’s third and 19 of 24 provinces in Ecuador. A portion of Colombian Southern and a piece of Brasilian Western also felt the shake. A 3-year-old boy passed away, there were dozens of wounded, more than thousand injured, and such other damaged or unhabitable buildings.

 

Peru’s Geophysical Institute (IGP, as its initials in Spanish), the official bureau watching and reporting if a quake happens, launched a notification on the social media just 8 minutes after many people jumped out their beds in the most occidental portion of South America. The information came from Santa María de Nieva, Amazonas Department, 60 miles to the west of the epicenter, 789 miles to the north of Lima City at the same time.

 

Although the major metropolitan area of Peru (wwith Callao) had felt an event with epicenter in the sea, 15 miles off its shore, about four hours before, it didn’t become to perceive much intense the Barranca, Loreto’s one. However, in Sullana, Piura, 410 miles to the west of Santa María de Nieva (and about 466 miles of the epicenter), the soil shook like a rocking chair for a minute.

 

 

If it already trembled, it will tremble again

Up to now, the science doesn’t have definitive tools allowing to predict when and where a quake is going to happen, but the previous behavior of the soil allow the scientifics to suppose what zones could rock right now or in the future, and more specific measures like the soil deformation ease to forecast where the epicenters could locate. It’s probability based upon statistics.

 

That’s why IGP has clear if Peru would be divided in two portions, one to the north and another to the south, the southern portion could have more than the double of probability to record a quake – 7 in 10 compared to 3 in 10 that the northern portion presents.

 

IGP’s CEO Hernando Tavera has explained many times this one doesn’t come out from one only observation but from years of surveys including the seismic silence, what means the absence of significant events those release the accumulated energy in the spots where the shifting of plates and faults have been freesing to critic levels. In fact, the bureau has forecasted that Lima and Callao must prepare for a 8.8 magnitude event due to a very strong quake has not happened in the area for more than 270 years.

 

Let’s add that if Peru, like all the western portion of the Americas, is part of the Pacific’s Ring of Fire, then the frame we get is reduced to resignation to the often happening of quakes. That’s why it has been insisting on citizen education about how to act if one of those developing events can save lives.

 

 

Learning in Mexico

However, the quakes are not almighty like the people believe and they also have a weak point. Since what is felt on the surface is basically a vibration and this is produced by spreading waves, the scientifics have achieved to estimate which speed they run once they reach the surface, from the epicenter in other words. The number varies according to the type of terrain and territory but the range goes from 2 to 4 miles per second (mps).

 

You can prove it not using instruments. If you live near the sea, a river, a pond, or any water body, and you see how the waves produce, there is a lapse of time between they break out until they get to a point, like the rim, for example. And there is another interesting fact here: the wavelength of the light, that allows you to see the waves, is quite faster than the waves themselves in terms of spreading time.

 

Regarding, the communications we use (the radio, the TV, the wireless telephone) travel or rather transmit almost at speed of light or the visible, and the scientists know the number: 186 to 217 mps… 50 times faster than a seismic wave! At least in Latin America, the first country that took advantage of it was Mexico after an 8.1 magnitude event struck near the lead of Balsas River, Michoacán, but what blasted strongly the Federal District.

 

On September 19th, 1985, 7:17 central time (1317 GMT), a hypocenter at 10 miles depth broke violently and rocked the central and southern half of that nation. But Mexico City, located 267 miles to the east of the epicenter, just perceived it at 7:19 central time (1319 GMT). Everybody knows that speed equals distance between time, what means that the seismic wave traveled between both points at 2 mps.

 

Upon that fact, the Mexican authorities have implemented since 1991 a radio antennas network connected to quake sensors. Time later, the system has been perfecting until a parameter that if the sensor detects a 6.0 magnitude and above event activates a public alert through the media, mobile applications, and a siren network in the cities of the middle and the south of the nation that, even provided the quake breaks out in the Pacific Rim of Mexico, can activate until 50 seconds before.

 

According to IGP’s CEO Fernando Tavera, and paraphrasing his Mexican colleagues, the rest is made by the citizenship that is constantly trained for just listened to the sound, it evacuates its house or the building where it is. Additionally, the construction codes changed after 1985 for the structures to be resistant to quakes.

 

 

The Peruvian plan

Upon that experience, Peru is implementing a 106-sensor network along its shores those will connect to a commuter at the National Center for Emergency Operations in Jesús María, Lima, that at this time will activate a siren network in the major cities of the country – it’s the Peruvian System of Seismic alert or SASPe, as its initials in Spanish. It is also expected that the rest will make the continuous quake & tsunami drills done every year.

 

The IGP has explained the alert activation is going to depend on the distance between the user and the epicenter. If SASPe had already working for the November 28^th, 2021 event, the alert in Sullana had activating 1 min 50 sec before the soil shakes, but if the user were closer to the epicenter, that time had reducing. For example, Jan, Cajamarca, 176 miles to the west of santa María de Nieva and 236 miles to the west of the epicenter, had receiving the alert 47 seconds before feeling the shake.

 

If the sensor had being in the epicenter area (an active seismic zone, actually), the time had lasting 12.5 seconds. All the times have been deducted by FACTORTIERRA based upon the available geodesy. Upon those same parameters, if SASPe had being implemented for July 30^th, 2021, when the 6.1 magnitude event shaking the whole Piura Department happened, and supposing that a sensor had being at the epicenter zone, Sullana City had being warned just 3 seconds before the shake.

 

It doesn’t seem much but the IGP believes the only fact of evacuating just when the siren sounds, it could save thousands of lives. SASPe will be ready just in 2023. It’s expected that rehearsals to be done during 2022. Up to then, knowing how to act if the soil trembles can make a difference between a scare or a disaster.

 

With reports of Andina and BBC News. © 2021 Asociación Civil Factor Tierra. All Rights Reserved. Comment this in the box below, or on our Facebook and Twitter accounts. Would you like to learn more? Write us at factortierra@gmail.com