I can feel it forming inside my stomach like it does after every trip to Lucky’s. My food baby, expanding and giving me stomach cramps. Each night, I get a gyro, I eat it too fast a food baby is formed. The chicken and tzatziki combination melts on my mouth and becomes too good not to finish as soon as possible. I devour the beautiful pita sandwich and for the rest of the night, I carry the burden of my food baby. Eventually though it will go down, once it’s digested but like it always does each night, it will rise. I will go out to eat those delicious gyros from Lucky’s, and it will happen again and again until I am forced to leave this beautiful island.
Like me and many others, volcanoes also form food babies except their food babies are called ground deformation (ground inflation). Deformation has the same affect a food baby has except the inflation occurs on the surface above a volcano rather than on the stomach. There are two possible reasons for deformation on volcanoes, hydrothermal boiling or magma rising. Each type occurs underground, and have similar processes, but they each create different hazards.
Hydrothermal deformation occurs in volcanoes from hydrothermal vents which are produced from ground water. These vents can be found almost anywhere on a plate boundary and are also common on volcanic hotspots. Geysers, like the one in Yellowstone National Park can produce from hydrothermal inflation as well as hot springs like the ones in Colorado (U.S.A) and Iceland.
Hydrothermal deformation is present when magma from below the surface boils the ground water (think boiling water on the stove). Heating the water then produces steam, which moves through the rocks thus causing the rocks to move (Fig.1). Along with expansion of the rocks itself due to the heat, inflation, or a rising of the ground surface, occurs. This inflation though, does not last long, but rather will occur in small bursts (like a food baby, it will leave without any extra effort).
Magmatic deformation occurs in the magma chamber but rather than occurring in small bursts, the ground stays inflated for long periods. When people gain weight from eating, they often have to exercise to rid the body of the excess fat, magmatic deformation has a similar process. When magma rises from the asthenosphere, it collects in a magma chamber. For thousands of years, the magma will collect far below the Earth’s surface. When the chamber becomes too full, it will either break horizontally and melt the rock surrounding it to create a larger chamber or it will begin to move upwards through cracks in the rocks. This upward movement of lava, along with the over filled magma chamber, generates inflation at the surface.
So, what are the hazards of these two processes? Like my food baby from Luckys gyros, hydrothermal deformation does not create any major problems. There may be a few panic attacks by the geologists that study the volcano if they cannot determine whether the inflation is hydrothermal or magmatic but nothing serious except shallow earthquakes close to the surface.
Magmatic deformation, though, is much more dangerous to livelihood of the surrounding area. Larger, deeper and more frequent earthquakes occur from magmatic deformation.A major consequence of magmatic inflation can include serious eruptions if the magma cannot expand the chamber from melting the surrounding rock. Hence, the magma would be forced to the surface generating an explosion (Fig.2). So when compared to weight gain, if the body (the magma chamber) cannot find another place to store excess fat (magma), it must be burned through exercise (explosions) to rid the body (chamber) of the excess fat (magma).
Now, here’s the 411 on how to determine whether the inflation is due to hydrothermal vents or magma chambers. Inflation as a result of hydrothermal vents will not last long and will usually release four main gases, H2S, H2, CO4, CO (Click here for more information on gases). Magma chamber inflation though, will not only be permanent until the magma is released but will discharge three different types of gases, HE, CO2, and SO2 (Vougioukalakis).
To measure the overall inflation rate, geologists utilize tilt meters to see how much the surface is tilting away from the magma chamber. The more, the tilt meter moves away from magma chamber, the higher the inflation (simplified inflation) cite. At Santorini there is a GPS benchmark where researchers can return to specific location and remeasure the elevational change of Nea Kameni (FIg.3). This tracker informs researchers of magma rising and deformation.
So what’s happening in Santorini? Between January 2011 and May 2012, there was not only an increase in earthquakes but there was an increase in inflation on the caldera floor, two kilometers north of Nea Kamerni. The caldera floor had a vertical uplift of roughly fifteen to twenty centimeters (Fig.4). The geologists who study Santorini concluded the inflation was sourced from five kilometers underground, which indicated the pressure was coming from the magma reservoir. They believed this was a warning sign for a destruction eruption that could occur soon here in Santorini (Vougioukalakis).
For most, food babies are burden, thSourcesey make people feel full and unappealing. While I tend to embrace my food baby around town, some choose to hide it. Researchers who examine Santorini chose to embrace the food baby that produced on the caldera floor in 2011/2012. Unlike most tourists and locals, some geologist are excited for a new eruption, to be able and see the volcano active once again. So, whether you embrace your food baby, or choose not to, it is important to understand the significance of health and safety. Nea Kameni is rumbling once again under our feet, and eventually, its food baby will escape, so make sure you brace your self for when it happens!
“Simplified inflation-deflation cycle of magma reservoirs at Hawaiian volcanoes.” USGS . USGS , 28 May 2010. Web. 17 June 2015. <http://hvo.wr.usgs.gov/howwork/subsidence/inflate_deflate.html>.
Vougioukalakis, George . Powerpoint Presentation. 16 June 2015.