Tajogaite 2021 Eruption (La Palma, Canary Islands, Spain): An Exceptional Volcanic Heritage to Develop Geotourism †

: In the Canary Islands, sixteen historical eruptions have been documented in Lanzarote, Tenerife, El Hierro, and La Palma. The latest eruption, the Tajogaite eruption, occurred in 2021 in La Palma and the richness and diversity of the natural and cultural heritage associated with this eruption can be a valuable resource for attracting visitors and tourists. The main aim of this work is to select sites of geotourist interest (SGIs) in order to create geo-itineraries. The methodology used is based on ﬁeldwork and drone ﬂight videos and photos taken during and after the eruption. Sixteen SGIs have been selected and studied. Eleven sites represent the geo-heritage of the Tajogaite eruption and seven sites are related to the surrounding natural and rural landscapes. In the near future, geo-itineraries (for in-person and virtual visits) will be created for visitors to La Palma and for the interested online audience.


Introduction
Volcanic eruptions have huge direct and indirect territorial implications both during and after the eruption process.Given the large footprint they create, the impacts of a volcanic eruption are commonly negatively assessed as threats, hazards, and risks.However, volcanic eruptions can also have positive impacts through the provision of strengths and opportunities for the society to be resilient against natural hazards.Volcanic landscapes offer multiple attractions for the population that coexist with them.Millions of people live in areas with active volcanoes [1,2], and their most important contributions include fertile soils for agriculture, geothermal energy, and materials for construction and tourism activities [3].For tourism, the diversity of natural and cultural heritage associated with volcanoes can serve as a major attraction [4,5].Previous studies have identified the resources offered by volcanoes for the development of volcano-tourism [6,7] into eight categories: scenery, the spectacle of volcanic activity, hot springs and spas, climbing and skiing on volcanoes, Proceedings 2023, 87, 26 2 of 8 ecology and adventure travel, black, red, and green sand beaches, and archaeology and religion [8].
In the case of the Tajogaite volcano, its eruption has caused huge damage to the local population, equipment, infrastructure, and economic activities, with especially negative effects on agriculture and tourism [9].However, the eruptive phenomenon and the new landscapes generated by the eruption demonstrate potential as new attractions for geotourism [10][11][12][13][14]. Therefore, the main aim of this work is to select sites of geotourist interest (SGIs) associated with the heritage of the Tajogaite eruption and surrounding volcanic landscapes in La Palma island in order to create real or virtual geo-itineraries in the near future.The use of the concept "sites of geotourist interest" is based on the research of Kubalíková et al. [15,16] which states that, for the purposes of geotourism, both geosites/geomorphosites sensu stricto and other types of sites can be considered.
In the case of the Tajogaite volcano, its eruption has caused huge damage to the local population, equipment, infrastructure, and economic activities, with especially negative effects on agriculture and tourism [9].However, the eruptive phenomenon and the new landscapes generated by the eruption demonstrate potential as new attractions for geotourism [10][11][12][13][14]. Therefore, the main aim of this work is to select sites of geotourist interest (SGIs) associated with the heritage of the Tajogaite eruption and surrounding volcanic landscapes in La Palma island in order to create real or virtual geo-itineraries in the near future.The use of the concept "sites of geotourist interest" is based on the research of Kubalíková et al. [15,16] which states that, for the purposes of geotourism, both geosites/geomorphosites sensu stricto and other types of sites can be considered.

Study Area
The Canary Islands are eight Spanish islands located off the west coast of Africa (Figure 1).The main economic activity is tourism, with an average of around 15 million tourists per year [17].The Canary Islands are volcanic islands with active volcanism under subtropical oceanic climate.Sixteen eruptions have been documented in historical times on Lanzarote (1730-1736 and 1824), Tenerife (1492, 1704-1705, 1706, 1798, and 1909), El Hierro (2011-2012), and La Palma (1480, 1585, 1646, 1677, 1712, 1949, 1971, and 2021).The last eruption occurred between 19 September and 13 December 2021 in the Cumbre Vieja volcanic rift (CVVR) on La Palma Island (Figure 1).The CVVR is one of the principal geologic and geomorphologic units of La Palma.This rift has a gable roof shape, elongated in a N-S direction, with a length of about 20 km, an altitude of 1950 m meters, and an extension of more than 220 km 2 .During the last 150 ky, eruptive activity has been concentrated in this part of La Palma [19], making it the most recent geological unit on the island with eight historical eruptions.The axis of CVVR is the location of most Holocene volcanic cones (cinder cones, phonolitic domes, spatter The CVVR is one of the principal geologic and geomorphologic units of La Palma.This rift has a gable roof shape, elongated in a N-S direction, with a length of about 20 km, an altitude of 1950 m meters, and an extension of more than 220 km 2 .During the last 150 ky, eruptive activity has been concentrated in this part of La Palma [19], making it the most recent geological unit on the island with eight historical eruptions.The axis of CVVR is the location of most Holocene volcanic cones (cinder cones, phonolitic domes, spatter cones) and eruptive fissures, and the ridges are dominated by piles of pahoehoe and aa lava flows from the volcanic cones located on this axis.In the coastal area, lava deltas are formed by lava flows jumping over a former cliff.Generally, the CVVR eruptions are basaltic, and fissural, with dynamics ranging from Strombolian explosive/effusive to phreato-Strombolian [20].The forms and processes of erosion and accumulation are associated with the presence of some gullies, fossil and active cliffs, alluvial and colluvial deposits, dunes, and the formation of small beaches [21].
Due to the high altitude (>1940) of CVVR, a wide variety of plant ecosystems are found, corresponding to the different altitudinal belts of the island.Plant species identified in this area include the Canarian xerophytic scrub and shrublands (Euphorbia canariensis, Euphorbia balsamífera, Rumex lunaria, Euphorbia lamarckii, Bituminaria bituminosa, Kleinia neriifolia), juniper woodland (Juniperus turbinata subsp.canariensis), some enclaves of laurel forests (Myrica faya, Erica arbórea . . .), and the Canary pine forests (Pinus canariensis) which are predominant along the entire axis and most of the slopes of the CVVR.
The inhabitants of La Palma have occupied this area from pre-Hispanic times to the present day and, throughout history, they have taken advantage of the diversity of the natural resources offered by ancient and recent volcanic landscapes.The rural to periurban settlement of the island is dispersed, with preferences for locations with fewer areas of steep topography such as the Valle de Aridane where the eruption occurred.Examples of rich cultural heritage that utilise the volcanic landscapes include the construction of traditional stone houses, traditional livestock farming, and agricultural practices, both traditional agriculture and market agriculture for export.

Fieldwork and Drone Flights Videos and Photos
Several fieldwork campaigns have been conducted during the years 2021 and 2022 since the beginning of the eruption, after the eruption, and during the "return to normality" recovery work phase, which is currently underway in affected areas.During the fieldwork campaigns, information was collected on the natural and cultural heritage of geotourism interest before the volcanic eruption, as well as those on that which was generated during or after the eruption.All the information obtained was collected in a field card [3] facilitating the identification and characterization of the natural and cultural heritage of the SGIs.Furthermore, during the eruption, several videos were recorded on eruptive styles (eruptive column, ash fall, cone collapse, lava flows, contact water-lava flows, etc.) and the formation of volcanic geoforms (cinder cones, craters, lava shatter rings, flows, lava tubes, lava channels, lava falls, lava delta, etc.).Once the eruption was over, several drone flights (DJI Mavic 2 Pro with camera Hasselblad) were carried out to take photographs and videos, enabling us to select and characterize the most representative SGIs for both natural and cultural heritage.This heritage is directly associated with the Tajogaite eruption and with the volcanic landscapes around the volcano and will form the basis of creating real or virtual geo-itineraries soon.

Results
The Tajogaite eruption is located on the west flank of the CVVR in the area known as Cabeza de Vaca.It is a fissural eruption that opened between 840 and 1100 m.a.s.l.[22].Several parallel fissures of NNW-SSW direction could be identified [23], with several aligning vents.The eruptive dynamics comprised Strombolian style explosions with eruptive columns varying from a minimum of a few hundred meters to a maximum of 8 km, as well as Hawaiian phases with lava fountains several hundred meters high [22,23].Several pyroclastic density currents (PDC) associated with the collapse of the volcanic edifice were formed during the eruption [22].The erupted products consisted mainly of lava and tephra of tephrite/basanite bulk composition [23].The main volcanic geoforms are associated with the formation of volcanic edifices and lava fields.The former includes one fissural scoria cone about 200 m high and 800 m in diameter with a volume of 36.5 ± 0.3 Mm 3 , a surface of 0.6 km 2 [19,24] and at least 9 main craters.Multiple hornitos have also been built at the northern base of the main edifice, and various effusion lava vents [25] that run from the east of the San Nicolás road to Las Norias along a length of 1.9 km.The lava surfaces covered an area of more than 12 km 2 [23] and are characterized by their morphological diversity.Aa, pahoehoe, blocks and balls lava flows, lava deltas, lava tubes, channels, shatter rings, jameos (collapsed lava tunnel), etc. can be recognized.
Sixteen SGIs on volcanic forms created by the Tajogaite eruption as well as sites in surrounding areas have been selected and studied (Figure 2 and Table 1), given the high geodiversity of the main edifice, minor secondary edifices, and the multiple lava flows emitted by the eruption.SGIs in this study include the geoheritage of the Tajogaite volcano (scoria cones, hornitos, fissures, lapilli and ash fields, lava fields, lava deltas, lava tubes, lava channels, jameos, paleo-cliffs, gullies, slopes, sedimentary deposits, cliffs, and beaches) (Figure 3) and natural (lava field and pine forest) and rural elements (traditional houses, stone walls, crops, and livestock) (Figure 4) of the area.
Proceedings 2023, 87, x 4 of 9 a surface of 0.6 km 2 [19,24] and at least 9 main craters.Multiple hornitos have also been built at the northern base of the main edifice, and various effusion lava vents [25] that run from the east of the San Nicolás road to Las Norias along a length of 1.9 km.The lava surfaces covered an area of more than 12 km 2 [23] and are characterized by their morphological diversity.Aa, pahoehoe, blocks and balls lava flows, lava deltas, lava tubes, channels, shatter rings, jameos (collapsed lava tunnel), etc. can be recognized.Sixteen SGIs on volcanic forms created by the Tajogaite eruption as well as sites in surrounding areas have been selected and studied (Figure 2 and Table 1), given the high geodiversity of the main edifice, minor secondary edifices, and the multiple lava flows emitted by the eruption.SGIs in this study include the geoheritage of the Tajogaite volcano (scoria cones, hornitos, fissures, lapilli and ash fields, lava fields, lava deltas, lava tubes, lava channels, jameos, paleo-cliffs, gullies, slopes, sedimentary deposits, cliffs, and beaches) (Figure 3) and natural (lava field and pine forest) and rural elements (traditional houses, stone walls, crops, and livestock) (Figure 4) of the area.

Discussion
Volcanic eruptions and the landscapes they generate are a geoheritage that demonstrates a natural spectacle with high geodiversity [4], which provides multiple tourist resources [6][7][8].In the case of the Tajogaite volcano, thousands of visitors came to La Palma to observe its eruption [13,14].After the eruption ended, thousands of tourists continued to visit the island to observe the volcano and its effects on the landscape and the territory.In fact, it became one of the main tourist attractions of La Palma in 2022 [26] (Figure 5).However, more time is required to accurately assess the effect that this eruption will have on the tourism of La Palma.
This eruption is unique, compared to the other historical eruptions in the Canary Islands, in that the entire growth of the Tajogaite monogenetic volcano has been monitored from its beginning to its end, which has provided valuable information for different scientific disciplines, including volcanic tourism.In this sense, we have important documentation on the formation and evolution of the eruption, its geoheritage, and its territorial effects.This fact turns the eruption into a laboratory to identify, select, and characterize sites of geotourism interest associated with the natural and cultural heritage created and destroyed during and after the eruption.In addition, virtual and augmented reality [27,28] can be applied to create geotourism products associated with the eruption event.For this reason, the selection of these important geotourism sites could contribute to the sustainable local development of La Palma through both in situ and virtual geo-itineraries, as with those that have been produced in other volcanic areas [28][29][30].

Discussion
Volcanic eruptions and the landscapes they generate are a geoheritage that demonstrates a natural spectacle with high geodiversity [4], which provides multiple tourist resources [6][7][8].In the case of the Tajogaite volcano, thousands of visitors came to La Palma to observe its eruption [13,14].After the eruption ended, thousands of tourists continued to visit the island to observe the volcano and its effects on the landscape and the territory.In fact, it became one of the main tourist attractions of La Palma in 2022 [26] (Figure 5).However, more time is required to accurately assess the effect that this eruption will have on the tourism of La Palma.
This eruption is unique, compared to the other historical eruptions in the Canary Islands, in that the entire growth of the Tajogaite monogenetic volcano has been monitored from its beginning to its end, which has provided valuable information for different scientific disciplines, including volcanic tourism.In this sense, we have important documentation on the formation and evolution of the eruption, its geoheritage, and its territorial effects.This fact turns the eruption into a laboratory to identify, select, and characterize sites of geotourism interest associated with the natural and cultural heritage created and destroyed during and after the eruption.In addition, virtual and augmented reality [27,28] can be applied to create geotourism products associated with the eruption event.For this reason, the selection of these important geotourism sites could contribute to the sustainable local development of La Palma through both in situ and virtual geo-itineraries, as with those that have been produced in other volcanic areas [28][29][30].
This study highlighted the rich and varied heritage associated with the eruptive event at Tajogaite and the current tourist demand that exists in visiting the volcano along with its territorial impacts.The identification, selection, and characterization of SGIs are more than justified as they respond to the demand for volcano tourism.It is necessary to propose the creation of virtual or real geo-itineraries, taking advantage of the selected SGIs, to show the exceptional volcanic heritage created through this eruption.This development undoubtedly enriches the geotourism sector, not only in the area affected by the eruption, but throughout the island of La Palma.
This study highlighted the rich and varied heritage associated with the eruptive event at Tajogaite and the current tourist demand that exists in visiting the volcano along with its territorial impacts.The identification, selection, and characterization of SGIs are more than justified as they respond to the demand for volcano tourism.It is necessary to propose the creation of virtual or real geo-itineraries, taking advantage of the selected SGIs, to show the exceptional volcanic heritage created through this eruption.This development undoubtedly enriches the geotourism sector, not only in the area affected by the eruption, but throughout the island of La Palma.

Conflicts of Interest:
The authors declare no conflict of interest.

Figure 2 .
Figure 2. Location of the SGIs associated with the Tajogaite volcano.The numbers are listed in the Table 1.Spatial data source: [18,19].Self-elaboration.

Figure 5 .
Figure 5. Visitors and tourists during (A-G) and after (H,I) the Tajogaite eruption.

Table 1 .
The heritage of the sixteen SGIs selected.Self-elaboration.

Table 1 .
The heritage of the sixteen SGIs selected.Self-elaboration.