The Hawaiian volcano Mauna Loa shows increased signs of seismic activity, which prompted authorities to raise its associated alert level to “advisory”.
The number of quakes reported beneath the volcano’s crust has shown a dramatic surge lately. Normally, around 10 earth tremors take place every week, but in the last fortnight there have been 40 signs of seismic activity, as reported by the U.S. Geological Survey (USGS) Hawaiian Volcano Observatory.
The shallow-focus, small-magnitude earthquakes take place as molten rock fills the two reservoirs situated underneath the basis. In the last year, experts have recorded them in the upper Southwest Rift Zone and west flank, but lately their number has grown.
As a result, geologists have raised the threat level from normal to yellow or advisory, which indicates that there is activity exceeding background levels, but at the moment an actual eruption is unlikely.
“We expect the seismicity to grow steadily and be more consistent and persistent, and even the rates to change before we forecast an eruption”, explained Frank Trusdell, a USGS Hawaiian Volcano Observatory geologist.
According to experts, the heightened seismic activity could last for months or years before lava actually erupts.
Currently a NASA team is located on the northern slope of Mauna Loa, and engaged in simulating a manned Mars mission. It remains to be seen if recent developments will affect their training.
In the meantime, authorities are keeping the volcano under constant surveillance, and due to recent technological progress, they will be able to predict the eruption one week in advance.
As a result, when the need arises, they will alert people and issue an evacuation order before the natural disaster can pose a threat to communities. Nevertheless, local residents must still keep in mind that the volcano is active, so it is highly important to increase preparedness.
In mass and volume, Mauna Loa is the largest volcano on the planet. It has erupted approximately once every 6 years, in the last 3000 years, and its most recent eruption took place between March 24 and April 15, 1984. The event was preceded by around 100 daily earthquakes, which occurred throughout an entire week.
Although there were no fatalities the last time the volcano was eruptive, in 1926 and 1950 its lava did destroy villages. As a result of its potential hazards, local authorities constantly monitor its seismic activity, and also analyze ground deformation resulting from accumulation of magma beneath the surface.
Whenever significant modifications occur in these values, alert levels are raised. GPS stations are used, but also strainmeters and tiltmeters which offer the most sensitive data but are prone to errors.
Also, Mauna Launa is part of the Decade Volcanoes program, which encourages extensive scientific research and heightened public awareness of the world’s most dangerous volcanoes.
Image Source: Flickr