Iceapelago

by Peter Brennan

  ‘Where was the biggest recorded earthquake?’ asked Ros testing his brother’s knowledge.

  ‘In Chile in 1960, and it registered 9.5. Happy?’ Simon had an encyclopaedic memory. His brother could rarely catch him out when it came to scientific facts. On the other hand, his awareness of general knowledge was poor. Too much time spent reading books rather than newspapers had taken its toll. Their training told them that a Richter measurement didn’t tell the full picture when predicting the impact on volcanic activity. Seismometers close to an epicentre can’t record reliable readings if the earthquake is too big. Neither can the Richter scale show how much damage a particular earthquake is capable of causing.

  ‘Ros, do you recall what we were told about earthquake prediction methodology?’

  ‘This was Laffino’s speciality,’ replied Ros. ‘He was strong on the theory that the business of predicting earthquakes should be based on the study of an active fault and, in turn, on an assessment of the seismic patterns before incidents. That means, we should plot the readings at and around the epicentre.’

  ‘Yes, it’s coming back to me,’ said Simon. ‘He also said that only ten per cent of large earthquakes are preceded by smaller foreshocks. Do you remember we studied the 2010 Haiti earthquake in detail? It was so catastrophic because its epicentre was only about ten kilometres from Port-Au-Prince and at a depth of only thirteen kilometres. Before that there hadn’t been an earthquake in Haiti since 1860.’

  ‘Gosh, I wonder if this is what is happening here?’ mused Ros.

  Simon continued. ‘We should try to find the files covering the 1949 and 1971 volcanic events. The records are stored in boxes somewhere back at the research centre. We dug them out a few years ago as part of the programme to locate the seismometers that were previously installed across the Caldera.

  ‘That should help us pinpoint where the stresses were on previous occasions and the location of the epicentres,’ said Ros.

  ‘Exactly,’ replied his brother. He continued, ‘Our event will be one of dozens of earthquakes being monitored by the US Geological Survey and other international bodies. We need to brief Carmen Ortiz at the Instituto Geográfico Nacional. She is probably as surprised as we are that this is happening in a hitherto inactive volcanic region.’

  ‘Didn’t Carmen work on the Canary island Volcano Monitoring Programme a few years ago?’

  ‘Yes, and she did the same job that we’re doing now. Carmen and her team developed the geochemical monitoring network that we rely on. She is the national coordinator for the ShakeAlert earthquake early warning system that’s being pioneered by the US Geological Survey.’

  ‘ShakeAlert? Is this a new cocktail or what?’ said Ros.

  ‘Where have you been? Not reading your scientific journals? This software is designed to give us advanced notice of seismic tremors. Such an early warning system could save lives.’

  It took two hours of fast walking for the brothers to reach the safety of their base camp. There were no further aftershocks. They had a late lunch of hard bread and soft cheese while they pondered the events of the morning and what the Caldera de Taburiente was trying to tell them. They would find out soon enough.

  When the brothers returned to their base it was no surprise to discover an email marked ‘URGENT’ on the centre’s main computer. It was from Mark Doyle at the Global Seismographic Network (GSN). It read:

  Simon, Ros,

  I see you’ve had a busy day. When you get a chance please call me as we’re getting other seismic readings in and around the other Canary Islands and in the mid-Atlantic. Actually, call me immediately.

  Mark Doyle was the academic equivalent of a pop star in the small world of volcanologists and had two big fans in the brothers Rodriquez. A Canadian, he was Head of Volcanic Research at the Global Seismographic Network, which is a network of 150 stations that collects real time data on earthquakes and manages emergency responses. Run by a consortium of 120 American universities, it provides free real-time data to many governments, academics and research centres, like the one on Pico de la Nieve.

  Doyle was called on by the major TV networks when volcanoes threatened local populations and wider communities as was the case when the Icelandic earthquake Eyjafjallajökull disrupted European air travel. Mark explained the volcano jargon that his fellow volcanologists took for granted but which was impenetrable to the general public. As a result, there was better public awareness about such things as vents, craters, cones, fissures, dykes, magma, lava and even pyroclastic flows, a fast-moving current of hot gases and volcanic matter that can reach speeds of over 700 kilometres an hour.

  Simon called him as another brief tremor rolled slowly through the building.

  ‘Mark, it is Simon and Ros here from the Pico de la Nieve research station.’

  ‘Hi there,’ said Mark in a friendly tone.

  While they had never met Mark in person, they detected a slight nervousness in his voice, though he was doing his best to sound calm. Mark Doyle was the most senior volcanologist at the GSN and was well-known in the volcano community as a quiet and cautious person. When he had something to say, it paid to listen.

  ‘I know you are trained volcanologists, but I think it would be helpful if I gave you a head’s up as to what we think might be happening. Is that ok?’

  ‘Sure, Mark. Go ahead,’ said Simon.

  ‘La Palma may appear to be a calm and picturesque island and a haven for hill-walkers, but it has a volcanic sting in its tail. Until about fifty years ago the island was one of the most active in the world. All the attention, and budgets I might add, have switched to Iceland and Hawaii given what we’re experiencing there on an almost daily basis. The Caldera de Taburiente and the fissures along the Cumbre Vieja ridge have been dormant for quite a while. We’ve perhaps taken our collective eye off that particular ball.’

  ‘What does that mean, Mark?’ asked Ros.

  ‘Since 1430, or thereabouts, the many eruptions on La Palma were explosions of ash and cinders with emissions of fluid basaltic lava. In the main, the cones that were formed were quite small, at least that’s what we can observe. Each eruption was preceded by earthquakes of increasing vigour and frequency that were felt all over La Palma. It appears that this pattern may be about to repeat itself. In fact, during the 1971 eruption at Teneguia there were almost one thousand tremors of varying intensity over a two-month period before the main eruption. Thankfully, that incident was relatively small and as early warnings were to hand there were no fatalities.’

  ‘You mean that what we felt earlier is a precursor to an eruption?’ blurted Ros.

  ‘I can’t say for certain, but you will need to be vigilant. On the basis of previous observations, we can expect small vents and fissures to open at random and at many locations. No doubt many more tremors will occur. What concerns me most is where the epicentre will emerge and more importantly the potential scale of a possible eruption. The readings we’ve to hand don’t give a clear enough picture as there are multiple possible sources. The volcanoes on La Palma have the potential to cause significant collateral damage if the eruptions are of a sufficient scale to cause major landslides and tsunamis.’

  Mark paused before he continued. ‘And to complicate matters, in the past twenty-four hours there have been many other low-level seismic readings along parts of the mid-Atlantic Ridge, and on the Canary Islands of La Gomera and El Hierro. All these zones have been stable for decades.’

  ‘What can we do?’ asked Simon.

  ‘You will need to cover quite an amount of territory over the coming weeks,’ said Mark. ‘Do you need additional help?’

  Simon spoke. ‘As it happens, two colleagues from our university are working not thirty kilometres south of us. After this call I’ll be speaking to Carmen Ortiz who heads up the Instituto Geográfico Nacional. She too will have seen the readings and will, no doubt, want to be on
the island before too long.’

  ‘That’s a good start,’ said Mark. ‘We’ll have to set up a plan to observe all the dormant volcanoes on the island. I’ll talk to NASA and see if we can get satellite capacity. I’ll also trigger the local earthquake alert response plan. If there are any more significant tremors expect a call soon from the Guardia Civil. Why don’t you talk to your colleagues and try to map out the areas across the Caldera and down the length of the Cumbre Vieja that you might cover. I’ll call you in the morning to review progress.’

  ‘That’s a plan Mark, or at least that’s the start of a plan,’ said Simon.

  ‘OK so, let’s talk tomorrow.’ Mark signed off.

  Simon grasped the import of the call and it scared him. ‘Ros, I think we’ve landed ourselves in something that’s going to develop into a major incident. I’m not sure we’re in any way equipped to deal with this.’

  Another mild tremor rolled through the building to support his observation. Ros’s phone rang. As their stress levels were rising, they both jumped.

  ‘Ros, this is Carmen Ortiz.’

  ‘Hi Carmen, we were just about to call you. Hold on while I put you on speaker. Simon will need to listen in.’

  ‘Hi Simon,’ said Carmen.

  While she was a good bit older than Simon and Ros, they knew her well as she was their PhD supervisor. As a result, they talked as colleagues rather than as juniors might to their seniors.

  ‘What’s your assessment?’ asked Carmen.

  Ros took the lead. ‘We’ve just come off the phone from Mark Doyle who told us that there has been seismic activity in a number of areas and La Palma may be part of a wider phenomenon.’

  ‘That’s true.’ Carmen was fully aware of what was happening.

  ‘He was being cautious of course’, said Ros. ‘There is no evidence to suggest there is any reason to escalate matters, but we need to assume the worst and be somewhat precautionary. What are your plans?’

  ‘I’m on the next flight to La Gomera as the research centre there is experiencing similar activity. When I arrive tomorrow morning we should talk further.’

  ‘Before you go Carmen, we may need support if matters start to escalate. Any chance of some reinforcements?’

  ‘Rest assured Ros. The main reason for my travelling to La Gomera is to get an overview of all the readings. We’ll focus our limited resources where they are most needed. The team here in Madrid has been put on twenty-four hours’ notice to travel and once I press the button we could send you a support team within five or six hours. I reckon between you and Claudine and Maria we’ve enough boots on the ground for the time being. OK?’

  ‘Fine, Carmen. Talk Later. Bon Voyage.’

  Ros put the phone down slowly. ‘Let’s talk to the girls and see what they have to say.’

  Maria and Claudine were expecting the call. They recapped the day’s events.

  Claudine suggested, ‘We could cover the ridge line south of Refugio El Pilar and I’m sure my aunt Margarida and her husband Damian will help. They know the mountains, and especially the National Park, better than anyone else on the island.’

  Simon interrupted, ‘We’ll need much more help. It is possible that several sites may need to be observed at the same time.’

  Maria joined the call, ‘Until we get resourced up, I’m sure Uncle Damian will allow us use his drone. He uses it all the time for his photography in the mountains.’

  ‘In the absence of a NASA satellite, a drone will certainly be useful. Please ask him to contact me as soon as he can. We’ll need to get images of any vents and fissures that may rise to the surface over the coming days and weeks.’

  ‘What do we need to do exactly?’ asked Maria.

  ‘Monitor, monitor and monitor,’ replied Simon.

  ‘What exactly?’ probed Claudine.

  Simon explained, ‘We’re fortunate that the island is peppered with a network of seismic monitoring devices, albeit some over thirty years old. They will help us pinpoint the centre of activity and, more importantly, the depth of seismic activity. I expect if the current tremors intensify, we’ll know very soon where we need to focus our attention. The added complication is that there may be offshore as well as onshore incidents.’

  ‘Our new sulphur dioxide devices have the potential to give us another layer of data. If magma starts to rise, as the plates beneath the island appear to be shifting, we might soon see new fissures. The devices will tell us the strength of the flow of one of the main gasses associated with initial volcanic activity.’

  ‘But what will happen if your fixed devices are in the wrong location?’ Maria knew the answer to her question before she got a reply.

  ‘They won’t be. The brothers Rodriquez are smart. You know that by now,’ said Ros.

  ‘We used the records of the previous volcanic episodes over several centuries to select where to locate our devices,’ said Simon. ‘Anyhow, we’ve a small stock of mobile devices that can be deployed wherever we decide.’

  ‘Providing you can get close to the source of the emissions. Volcanoes can be hot you know!’

  ‘Yes, of course. But given the current low-level nature of the seismic readings we’re a long way off a volcanic eruption. So please rest easy,’ said Simon trying not to worry the sisters. He continued. ‘The one caveat is that we’ve limited cover in the National Park because there has been no volcanic activity there for as long as records have been kept.’

  ‘That’s encouraging,’ remarked Claudine.

  ‘It would be, but for the fact that the initial seismic reading suggests the source of the problem lies deep beneath the National Park,’ replied Simon.

  ‘Don’t forget to ask Damian to phone me as soon as he can. The thermal imaging feature of his drone could prove to be valuable.’

  ‘Will do,’ said Claudine.

  Minutes later Damian called. ‘Hi guys. I gather my latest toy may be of some assistance. How can I help?’

  ‘Damian, I’ve a hunch,’ said Simon

  ‘I thought you scientists only did evidence!’

  ‘Ha Ha. While everyone assumes that our problem may manifest itself close to the old Cumbre Vieja volcanoes, I’ve a suspicion that the real source may be closer to the base of the Caldera de Taburiente that has been inactive for tens of thousands of years.’

  ‘I’m listening. Where do I fit in?’ Damian was impressed that the brothers were taking the initiative.

  Simon explained, ‘It could be days, months or maybe never before an eruption starts. If the patterns that we know about from Hawaii’s experiences are replicated here on La Palma, the first evidence of an eruption will be a gradual phenomenon. What we need to detect are any rises, however small, in the surface temperatures.’

  ‘That’s where my drone’s thermal imagery feature comes in, right?’

  ‘You’ve got it in one,’ said Simon.

  ‘To be honest I’ve never had reason to use this feature,’ said Damian. ‘Whatever about checking body heat at night, the drone wasn’t designed for volcanic surveillance.’

  ‘Could you test the drone this evening? Once you get used to the controls let me know. If you could transmit the data to us using the drone’s Wi-Fi; that would be a great help. It would be better if we could see the data in real time.’

  ‘Ok Simon, I’ll put the drone through its paces after dinner. Have you any specific locations in mind? You know the drone’s range is limited. I reckon I could keep the beast in the air for no more than forty minutes.’

  ‘That should be more than enough for starters. I suggest we focus our efforts at the base of Pico de la Nieve and the western end of the National Park. You might plot a crisscross grid that can be tested systematically. We can adapt the size of the sample area depending on developments. We can schedule a call once you have some results.’

  ‘That
suits me as I may be tied up with groups of hikers for the next two days.’

  The River Corrib

  As soon as Sean had signed off, Lars turned and spoke to the audience seated across the expanse of the Big Room. All available chairs and benches were occupied. There was a buzz of conversation as everyone tried to grasp the import of what they had heard.

  ‘We need a plan.’ While he was in marketing mode, he didn’t really need to be. Whatever Lars recommended would not be challenged. His colleagues and the research students held him in the highest regard. His reputation as a fair, competent and professional project leader and world-renowned climate scientist didn’t require elaboration or explanation.

  ‘We’ll take delivery of a thousand ice-melt monitors, for the want of a better term, in late August. Once they arrive, we’ll have three weeks to get them into place before we close up shop for the season. We’ve worked at five principal sites for the past few years, most within easy reach of the Summit Station. To get the results we require, I believe we need to disperse the golf balls across a wider footprint of approximately 300 kilometres radius from here. I want twenty locations identified across the width and breadth of the ice sheet within that footprint. What we’re looking for are large crevasses or sinkholes that have a good proven flow rate based on your observations. We need to select priority sites that have the potential to generate the data we need. That means we should split into several teams, with two or three a team. Can you break into five groups and talk through the logistics of doing what is needed in a safe manner?’

  Before they set about this task, Alice, ever the enthusiast, chipped in.

  ‘We already know some of the potential locations are unstable. If we can’t get close to a crevasse could we use the drone to survey potential sites and perhaps more sophisticated equipment to deliver the payload?’