Unknowncountry Weekender: Earthquake Swarms and Supervolcanoes–Should We be Worried?

There is earthquake activity around two supervolcanoes, one in North Korea and the other in the United States. Earthquake swarms in such areas can indicate magma movement, and scientists are studying both volcanoes. A thousand years ago the eruption of Mount Paektu in what is now North Korea was probably the largest in human history. The eruption of the Yellowstone Supervolcano would devastate the United States. In addition to these two restless supervolcanoes, large-scale earthquake activity is continuing. Like the meteor count Unknowncountry reported on earlier this week, the earthquake count has been rising worldwide for a number of years.

On September 24th, there was a huge earthquake in the Arawan province of Pakistan which measured magnitude 7.7 on the Richter Scale and resulted in the deaths of over 500 people. The tremor caused considerable damage, levelling over 1500 houses and trapping people inside. The quake has left dreadful conditions for survivors, many of whom have been left without even basic shelter from the scorching sun due to the scale of the damage.

Astonishingly, out of the carnage, something new was born: a small island appeared out of the sea in the Paddi Zirr, which is a stunning, ‘hammer-head’ shaped bay leading out into the Arabian Sea. The new land mass is estimated to be approximately 75 to 90 metres in diameter and 15 to 20 metres above sea-level. The new-born islet is not thought to be a permanent feature and it is predicted that it will eventually erode away over the next few years.

The after-shock of the larger quake, which occurred later the same week in the Balochistan region of Pakistan, 18 miles south-west of Arawan, was equally violent with USGS declaring it 6.8 on the Richter Scale, and Pakistani authorities scoring it even higher at 7.7. At least 15 people were killed as a result of the second tremor, and Chief Pakistani meteorologist Arif Mahmood warned that such tremors might continue for the next few weeks.

Data published by the USGS (United States Geological Survey) seems to indicate a swarm of earthquakes in the Pakistan area, particularly in the Awaran area, and also, less widely reported, a significant cluster of tremors registering above 4.5 magnitude located further North in Afghanistan.

In the United States, seismic activity has increased around Yellowstone National Park. A University of Utah press release revealed that a disturbing total of 130 earthquakes had rocked Yellowstone National Park between Sept. 10 and Sept. 15, though as the quakes only registered between 0.6 and 3.6 magnitude, most were too minor to be detected without the aid of specialist equipment. Seismic activity in the Park is often experienced in swarms, and during the period in question three separate swarms were detected, mostly concentrated around Lewis Lake, the Lower Geyser Basin and northwest of Norris Geyser Basin.

The significance of this is that Yellowstone Park is a notoriously volatile area which sits atop an immense, active volcano. The caldera, or ‘cauldron’ of this volcano has shown signs of rising over the past few years; scientists say that this is due to magma rising and pushing up on the caldera, or from magma heating gases and hydrothermal fluids – the same fluids that spew from Yellowstone’s Old Faithful geyser – and pushing them against the caldera.
This volcano is known to have produced some of the most colossal eruptions in history, so any increase in seismic activity around it must surely be taken seriously. Bob Smith, a geophysicist who has monitored seismic activity in the area for the past 53 years, said that the recent increase in activity was "unusual".

At the very least, previous major tremors at Yellowstone have been known to trigger geyser eruptions; a major quake at Hebgen Lake in 1959, registering 7.3 to 7.5 magnitude, changed the interval of Old Faithful eruptions and caused nearly 300 locations within Yellowstone to erupt. Bob Smith has apparently traced all three recent swarms back to the Hebgen Lake quake, as aftershocks can sometimes continue for hundreds of years.

Another potential volcanic threat is the Mount Paektu volcano, on the border of North Korea and China. Its last eruption 1,000 years ago was one of the largest in human history; the whole top of the volcano blew off and consequently seismologists have always viewed it with respect. Chinese scientists have been studying it for the past 15 years, particularly after signs of significant activity occurred in the year 2000. At this point, its sides were actually seen to bulge, and there was an increase in earthquakes in the area, often an indicator of an impending volcanic eruption.

Seismologists are now embarking upon a study of the volcano, during which they will attempt to look inside it using a process similar to a medical CT scan, in order to form a more complete picture of what is powering the volcano, and to establish the threat of eruption. Six seismometers were set up in August, and the full data should be available by August next year.

Data from Earthquake-Report.com indicates that there has been an increase in volcanic activity in multiple sites across the globe: at the Cumbal volcano in Colombia seismicity is at an elevated level; ‘mini-crises’ continue to frequently occur at Momotombo volcano in Nicaragua and also in Nicaragua the Telica volcano finally erupted on 25 September after nearly a year of vigorous seismic episodes. Tremors associated with volcanic activity continue to be felt at Pacaya volcano in Guatemala and at White Island (New Zealand), and a very strong earthquake was recorded on 30th September in the Kermadec Islands in the South Pacific.

This data serves to illustrate that unless earthquakes or volcanoes affect populated areas, then they are not considered to be a threat to human safety and consequently are not often widely reported, but should these incidents be assessed individually, or should the earth’s seismic activity be assessed as a whole if a global increase is identified? The USGS, currently operating at reduced capacity due to the recent Federal Government Shut Down, identifies on average around 50 earthquakes per day across the planet – that’s 20,000 per year – so perhaps the quantity recorded is not so significant, but when swarms of sizeable activity occur in concentrated areas at similar times then should seismologists begin to sit up and take notice?

The science is very complex, however, and even when a swarm of earthquakes manifest in one region, scientists claim that it is still very difficult to predict whether these are the precursor to ‘something bigger’, or whether they are connected to other activity. Surely, though, given the potential threat that major earthquakes or volcanic eruptions pose to our global civilisations, isn’t it best to err on the side of caution when assessing the dangers? This is clearly a view shared by the Italian government after they jailed six Italian scientists and one government official for manslaughter in 2012; the team of seismologists and geologists were accused of not giving the Italian public enough warning of an impending earthquake in 2009 which killed over 300 people.

Even if scientific analysis is able to predict a future seismic event, the evacuation of thousands or even millions of people is not always going to be possible. Each and every day, millions of Californians live perched on top of the San Andreas Fault, despite a study earlier this year which warned that a ‘mega-quake’ in the area was a possibility. The research focused on a section of the fault called a creeping segment which lies about 50 miles east of the coastline, between Paso Robles and Monterey. The creeping segment, similar to another major fault in Japan, was long believed to have been steadily slipping and releasing pressure as tectonic plates shifted. Researchers now believe it has the potential to build up stress over time and then rupture.
At the end of the day, we must never forget that we live a precarious existence, inhabiting a constantly evolving planet within a volatile universe. This reminds us how important it is to respect the amazing, living organism that constitutes our wonderful Earth, and to use science to explore ways in which we can continue to live in harmony within its various eco-systems and developing landscapes. Man may be considered to be the dominant species on this spinning sphere we call home, but we must always humbly defer to Mother Nature as she is ultimately in charge of our destinies.

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