Pico Partido: Volcanic perfection in the Canaries

Dr Trevor Watts (UK)

Lanzarote is the easternmost island of the Canaries, less than 100 miles (about 150km) off the coast of Morocco. It is part of Spain, but not officially in the European Union and Pico Partido is a sharp, prominent peak near the centre of the island, between the small town of Mancha Blanca and the volcano of Timanfaya. The name means “divided mountain”, so called because the high peak is split by a deep fissure that seems to chop it in two. And it is enthralling. It is a basket of volcanic jewels to be treasured, particularly after the disappointment of the lack of access to Timanfaya itself (of which, more later). And Pico Partido is accessible, unlike much of the island where too many roads have no lay-bys or even a patch of cinder where you can pull in and explore.

The geology of Lanzarote

Lanzarote, with its volcanoes, is sitting on the tectonic plate that forms most of Africa. It is not near the edge, so it is not formed by one plate sinking under the other. Nor is it above a rising mass of magma, a hot spot. A little surprisingly, it is on a line of fractured rocks that stretches to the Atlas Mountains in North Africa, and further over to the European Alps.

The fractures formed, and are still moving, as a result of the stresses created as the African plate collides with the European plate. The volcanoes rose through the old sea bed about 2,600m below. For around 30Ma, the undersea eruptions built up until they broke the surface about 14Ma, in the middle of the Miocene. Eruptions have been sporadic ever since, sometimes pouring vast amounts of lava from a series of fissures for several years. At other times, there were huge explosive eruptions. Landscapes were formed, eroded and buried repeatedly. The whole picture is extremely complex, especially as the chemical make-up of magma chamber seems to be unusually varied, giving rise to many different kinds and compositions of lava.

The history of volcanism on the island

There had been no eruptions in historic times and, in fact, a period of calm had lasted for several hundred thousand years. Therefore, one night in 1730, the sudden mass of eruptions down the centre of the island came as a huge surprise to the unfortunate islanders. Over the next six years, at least 50 volcanoes erupted, some explosively, others with fast-running lava that swept over 26 villages and fertile farmlands. A quarter of the island was destroyed as the volcanoes competed to bury and overflow each other with lava and ash. Timanfaya began on 1 September 1730 and ended on 16 April 1736, one of the longest-erupting vents on the island.

Pico Partido had a much briefer life, beginning on 10 October 1730, and ending less than four months later, on 1 January 1731. So, if you’re up there on the 10 October, you can sing “Happy Birthday” to a mountain. How do we know? The priest of Yaiza village wrote lengthy eyewitness descriptions of the whole thing and his informative writings are supported by the official accounts of the local municipal authority.

Pico Partido created three linked cones, each having periods of explosive activity with ash and cinders, pouring lava from tight vents, or filling their craters with lava lakes that overflowed their lips into the surrounding countryside. Cracks in the walls of the volcano filled with lava and erupted as small side vents. As the lava rose through the cracks, the gas within it expanded and blew out the top-most lava, spitting it out onto the surface. This built up around the vent, forming tall, steep-sided mini-volcanoes known locally as “hornitos” (Spanish for “little ovens”).

They are also called “spatter cones”, because of the way the gas spat out the lava. Several are seen on the flanks of Pico Partido, and more around Timanfaya. Further afield, some really good ones can be seen at Los Muchachos on another Canarian Island, La Palma, and at Fleener Chimneys in Lava Beds National Park, in the western USA. Here, on Lanzarote, the main lava flows are often crusted over, with the lava continuing to flow below the surface. The surfaces would sometimes collapse, leaving channels and caves, or “lava tubes”. Several such tubes and channels are found around Pico Partido.

Current Status

The landscape around Pico Partido still looks almost as fresh and newly-formed as it did in the eighteenth century, because there is so little rain to cause erosion or support the growth of vegetation. But this mountain has been quiet since 1731. There has not been any volcanic activity anywhere on Lanzarote since 1824, when there was a little series of eruptions. The last one, Tinguatón, erupted for only eight days in October 1824. Now, the only signs of life are the thermal hot-spots buried within several mountains, including of course, Timanfaya. In the restaurant at the top of Timanfaya, they use the heat from the lava to grill chickens, set fire to brushwood and make fake steam spouts for tourist entertainment, just to prove it really is hot just below the surface.

So, they’re not expecting an eruption soon? Maybe not, but neither were they expecting anything to happen in 1730, the day before the start of the second-longest eruption in recorded history (after Pu’u O’o in Hawaii). Incidentally, the Lanzarote volcanoes were spewing lava from a 14km-long fissure, the third-longest known (after those at Laki in 1783 and Eldgja in 934, both in Iceland).

Getting to Lanzarote

Arrecife airport is a four-hour flight from England. Charter flights operate from Birmingham on Thursdays and operate from other European cities on other days. We (my wife, Chris, and I) flew on a package with Cosmos for about £400 per person, including self-catering accommodation at the Sun Park Aparthotel at Playa Blanca, on the south coast. Car rental for six days costs about £130 plus a tank of fuel and there are several local and international rental companies operating throughout the island, offering good rates for one day or longer. They also all seem to have plenty of cars, so it may not be necessary to book in advance.

A tour of Pico Partido

Driving north from Yaiza along the LZ67, you pass the large pull-in for the camel rides and museum on the left. Going through the National Park, you pass the left turn along the side road to Timanfaya. About 2km further on towards Mancha Blanca, Pico Partido is very clearly seen to the right. It is easily recognised by its distinctive pale lava flow, which is cut down the middle by the dark, narrow split of a drained-out lava channel.

On the left, there is one of the “devil” signs at the foot of the Montana Tingafa cinder cone. (As you can see from the picture, these are cut-out signs at the side of the road. They are in the form of a dancing imp or little devil, and they personify the volcano of Timanfaya, and designate the boundaries of Timanfaya National Park). This is the northern boundary of the National Park. Right next to the sign, there is a flattened area of ash that serves as a car park for one or two cars.

There is another, slightly larger, space for parking about 50m further on. Be careful as you drop off the road onto the cindery surface. This is not a good place to rip off your sump guard or exhaust. A car that pulled in next to us reversed without checking the ground very carefully, and the driver found his back end perched on a boulder.

As an aperitif, a very easy track goes round Tingafa’s cinder cone and into the wide open crater on the far side. It takes about half an hour to walk it, plus photo stops. However, for the main course, you need to look across the road, and see Pico Partido with its pointed peak and sand-coloured lava flow. That is where we were heading.

Cross the road and walk about 20m south, towards Timanfaya. Look into the lava field for the start of the trail. It is quite faint at first, but then clear and a metre or so wide. Walking along it, you pass through the field of rough and jumbled a’a lava that came from the nearby Montańas del Senalo. (A’a lava is a solidified lava flow with a very rough or clinker surface.) The lava gives way to a loose cinder area in less than a kilometre. To your left, there is some smooth, poorly formed pahoehoe lava. (In contrast to a’a lava, pahoehoe lava is a lava flow with a thick, smooth, wavy surface, formed by low-viscosity lava.)

A broad, shallow channel runs through it like a wadi. It is flat-bottomed and almost filled with fine ash and cinder, so it is easy to follow it up the mountain. Gradually, it narrows and the sides overhang considerably in some places, where a complete tube had almost been formed. It can be a bit of a squeeze to get through in some places, but the walls show some lovely patches of lava dribbles that formed as the level fell when the channel finally drained out.

At the top, the channel becomes completely enclosed, forming a tube. In places, there are two or three tubes on top of each other, from different phases of eruption. There are drops of 10m or 15m from the upper and middle levels into the lower tubes, so you need to be careful. This is especially so when trying to get out of the lowest sections of the tubes, where there is serious risk of scraped and punctured shins, knees and palms.

From the very top of the channel, you need to back-track a few metres to climb out of this conduit. From here, you climb upwards to the left, and are quickly overlooking the old lava lake in the main crater. It is easy to walk onto the old lake surface and explore among the metre-thick sheets that remain now like black ice floes contorted over each other. They were twisted out of position as the lava below drained away and the surface collapsed. The old surface is now “perched”, creating flat-roofed caverns to explore, adorned with acres of dripping roof panels, like heavily-Artexed ceilings.

The walk up the left rim of the crater is also easy, over firm ash along a clear track. All along, you have superb views down to the shattered surface of the lava lake on your right.

Once you have reached the shoulder of the rim, it is possible to walk to the right and, further upwards, to a tall, ragged hornito. This is a spatter cone where lava was spat out and then dribbled down the slope towards the lake. From here, I walked along the ridge up to the rim of the far crater. However, this part is rather risky, as there is no track, and several parts are very exposed, with long steep drops down to the lava lake surface. The footing is very unsafe, especially when climbing up the final fissure to the high rim. However, the view from the rim is exceptional in all directions.

From this high point, it is possible to continue all the way round the lake, and return to your vehicle down the opposite curve of the rim. This also is not an easy or risk-free route, because it crosses another very exposed slope with loose rocks and a steep drop down to the lava lake. I watched a group of French and Dutch students taking this route very gingerly, but, fortunately, they all seemed to be intact when they reached the bottom.

Instead of doing this round trip, we retraced our steps and spent a short time exploring along the remains of a huge collapsed lava tube that must have been 30m across. It resembles a very rocky canyon, stretching to the east, going hundreds of metres down the far side of the volcano. This was a good place for our lunchtime picnic, we decided, sheltered from a strong and dusty wind among the large boulders that are scattered around.

Going back down to the shoulder, we climbed the smooth ash slope in front of us. This brought us to the rim of the third crater, with a terrific view into its depths. It is deep, with sheer faces. At the bottom, we could see the very small point where the lava erupted from the ground and flowed rapidly away to the north, burying great swathes of the surrounding area, almost down to the coast.

We walked along the left (western) rim of this elongated crater for several hundred metres. Part-way along, there is another hornito perched like a watchtower with vertical sides on the very edge of the crater’s rim. It is a really good example of a fresh-looking spatter cone made of sticky lava that didn’t move far when it landed.

A few metres below the crest, there is a metre-high cairn of pale green crystalline rocks. These are balls, or “xenoliths”, of a mineral called olivine that was embedded in the upwelling lava. These illustrate the very mixed range of lavas in the area. Exceptionally, they are up to 15cm across.

Eventually, it was time to leave this high area of interlocking crater rims. So we dropped back down the steep ash slope in the general direction of the distant car park. Just where the slope becomes less steep, there is a turn to the right along a level, clear trail. This skirts the lower slopes of the third crater. Gradually, it begins to rise, curves round the northern face of the cone and drops into the crater, just above the eruptive vent. Getting a bit short of time, we retraced our steps part of the way back along the trail, then cut off across the lava and cinders straight towards the car park – you really can’t get lost – the car park is visible from the whole of the walk.

On the way, there were two more hornitos, bigger than the others we had encountered. Each of them was made of a mixture of spatter blobs and coiling twists of pahoehoe-type lava. They seem to have oozed lava in their final days, rather than spitting it out energetically.

The whole area below these hornitos is covered in twisted pahoehoe lava that looks as fresh as the day it was created. Keeping the distant car in sight, we wandered over the lava, finding some beautiful tongues of pahoehoe lava in which each coil was 20cm across. Others were much more delicate and, when standing on them, you had to be careful not to break some of the fragile formations.

There are also areas where the lava swept down the slope in wide sheets, and solidified in smooth blankets of rock that enveloped everything beneath. Some parts are hollow, where the underlying lava drained away to leave a thin crust, sometimes creating miniature lava tubes, perhaps a foot wide, with broken sections like windows to see inside. Towards the lowest part of the slope, there is another large collapsed tube.

It is possible to clamber down into it and explore uphill into three stacked and overlapping tubes, but the ground is extremely unstable with innumerable and very sharp points. Lower down, the lava dived underground almost vertically, leaving an entrance about 2m across. It is surrounded by multicoloured lichens, and it plunges into a deep cavern. This one really looked too dangerous to explore without any equipment, so we contented ourselves with photographs into the depths.

Just past this deep tube, there is a major change in the topography. To the left, the smooth, ropey lava gives way to a broad slope of ash. Strictly speaking it is “lapilli” – loose pea-sized cinders, thrown out during one of the volcano’s little mood swings.  Both the pahoehoe lava and the ash field end in a 5m high face of rocky, blocky a’a lava. This is the edge of the flow that we walked across when we left the car park. Walking back directly across this seemed pointless – or too pointed, depending on how you look at it. Besides, it seemed to be the province of a very large black bird that had no fear of us – a raven, we thought. So we walked below the face of the flow until we came to the original trail that we had first used. From there, it is only a ten or fifteen minute stroll back to the tiny car park at the base of Montana Tingafa and a very welcome cold drink from the coolbox in the boot.

Other volcanic highlights

There are so many! If you can make sense of the awful maps and non-existent road signs, you might try:

1. Hervideros on the south-west coast: for turquoise seas that erode caverns in basalt-column cliffs; for the most beautiful line-up of lava bombs that ever formed the edge of a pathway; for walls of naturally coloured lavas built with love by local craftsmen; for divine pahoehoe lava twists; and for busloads of incredibly loud visitors.
2. The huge abandoned quarry at El Mojon: for layers of wondrous, fascinating exposures of pyroclastic deposits, carved by chance into very photogenic shapes by miners and the weather. You can wander around freely all day and not meet another soul.
3. El Golfo: for a gorgeous sea-flooded crater and wonderful layers of pyroclastic and wind-blown ash deposits that have been exquisitely etched out by the winds.
4. The Mirador del Rio, on the north-west coast: for wonderful views of the island of La Graciosa, with its cones and lava flows eroded into beautiful striped patterns.
5. The National Park and Timanfaya itself is spectacular, but we found it disappointing. You have to go round in a bus. Ours stopped very briefly several times to allow photographs to be taken through the filthy stained windows, before lurching off without warning. Just don’t expect too much.
6. We also went on a helicopter flight. It went straight across the National Park and along parts of the coast. We hurtled over the landscape at some speed, with no diversions, and little opportunity to admire the superb scenery because the pilot didn’t bank the helicopter around. Therefore, if you are on the back row in the middle, you see almost nothing – certainly not enough to justify the high cost of the flight. You will notice that I still feel a bit sour about this!

Further reading

Lanzarote by Raimondo Rodriguez, published 2003 in English. An excellent book that covers the Geological Origins and other aspects of the island.

Lanzarote, Canary Islands by Trevor Greensmith. Geologists’ Association
Guide No. 62, published in 2000 with monochrome photographs.

National Park – Timanfaya – Visitor’s Guide, published in English by the
National Park in 1997.

Lanzarote Tourist Guide by RL Varela is one of the Recuerda Series. It is
undated but readily available in English.

Los Volcanes De Las Islas Canarias by V Arana and JC Carracedo, published in
1978 in Spanish.

Volcanes de Lanzarote by Reiner Loos published in 2000. This focuses on the
Parque Nacional de Timanfaya. It is mostly colour photographs with some text in multiple languages.

Volcanoes of Europe by Alwyn Scarth and Jean-Claude Tanguy, published in
2001 with very informative text, diagrams and photographs.

Map – Lanzarote on a scale of 1 : 62,500 by Guias y mappas Raimundo. This map is a sepia-style satellite image of the island that shows all the volcanoes in shaded relief. Worth buying to admire as much as to use.