Abstract
TT 209 was built in a wadi, a location that means it has been affected by flash floods since ancient times. The team in charge of its study and conservation has initiated a systematic programme of environmental data collection (temperature and relative humidity) in order to understand the natural conditions of the tomb and any transformations caused by archaeological work in its underground chambers, as well as to inform future conservation. These statistics can also be useful for excavation and conservation programmes in nearby tombs whose architectonic structure is similar and have also suffered from exposure to water damage.
I am now living in a grotto at Thebes & much inclined to give the Troglodytes my praise for their good sense in choosing these abodes which present a uniform & unvaried temperature both in summer & winter.
TT 209 is a tomb of the Late Period located in the West Bank of Luxor, in the sector of the Theban necropolis dubbed South Asasif by archaeologists (fig. 1). It was one of the least known from the group of medium-sized late tombs when the activities of the Misión Arqueológica de la Universidad de La Laguna (MAULL) began. The distribution of the underground chambers had already been identified in studies by Dieter Eigner, but our excavations have considerably broadened knowledge about its layout, recognizing larger and more complex architectural structures both on the surface and excavated into the bedrock (fig. 2). Based on the documentation obtained through our fieldwork, we have proposed that TT 209 was built during the Kushite Dynasty, possibly in its early stages, for a senior official who performed his administrative duties in Waset/Thebes, current Luxor. He was of Nubian origin and his name can be read as Nisemro (along with other, less likely, possibilities). 2
Exterior of the site, seen from the south, at the end of the third excavation season.
Plan of the underground chambers of TT 209, at the end of the fifth season, with the architectonic innovations identified by the MAULL, and the name of the chambers where the register instruments where placed (drawing: S. Pou Hernández).
TT 209 is located on the northern slope of the Wadi Hatasun, halfway between where it rises in the Valley of the Colours and where it enters the fields beside the southern wall of Ramesses II’s Mansion of Millions of Years (fig. 3). Access to its underground chambers is from a south-facing door opening onto a courtyard. Both of these features – the wadi and the orientation – have to be taken into account for the analysis of environmental conditions studied in this article.
Wadi Hatasun (photo: J. M. Barrios Mufrege).
The wadi is the drainage channel for rain that fell, and still falls, into a sedimentary basin that extends from the eastern side of the Theban Mountain and the southern slope of Shaykh ‘Abd el Qurna to the northern hill of Qurnat Mara‘i. Sediments carried by rainwater have been deposited in the bed of the wadi since antiquity and were extensive enough to completely cover the site during the Roman Period. 3 Under unknown circumstances, the inner chambers must have been discovered at the turn of the nineteenth and the twentieth centuries and were partially excavated by Robert Mond and Percy E. Newberry between 1903 and 1904. Carelessly a trench between the bed of the wadi and the entrance was left open. Water and sediments have entered the underground chambers through this channel, filling them. This provided an urgent reason to document TT 209 before it was completely buried again. The La Laguna Mission had to excavate at the location of the courtyard before discovering the door to the internal chambers at the end of its first season. We were then surprised by the high level of relative humidity inside the tomb. We were also concerned about the possible deterioration of the walls and ceiling surfaces due to the exposure to wet sediments and a too fast drying process that would cause the growth of carbonate concretions.
These were the circumstances that led to starting a systematic register of temperature and relative humidity data in the inner chambers of the tomb, as well as its surroundings from the second season. The objective is to have accurate information on the changing environmental conditions of the site. TT 209 has become an active agent of the proyecto dos cero nueve research, opening a way of analysis on climate that had not been initially planned. 4 This article presents the results of these measurements from various perspectives:
Characterization of the ‘natural’ environmental conditions, that is, without archaeological intervention, in the inner chambers.
Identification of temperature amplitude and humidity oscillations inside the tomb during daily and annual cycles.
Control of environmental variations produced by the team entering the chambers daily during archaeological seasons.
Recognition of the modification of micro-environmental conditions produced by the removal of the sediments that filled the chambers, which were still wet following the last flash flood in the wadi.
These datasets, mainly those of relative humidity, are the reflection of the relationship that archaeologists and neighbours of the nearby hamlet of Hurubat have maintained with TT 209. 5
After it was discovered at the turn of the nineteenth and twentieth centuries, the tomb should have taken on the functions of a patrimonial asset. However, the value placed on undecorated monuments (TT 209 is in fact decorated, but this went unnoticed) at the beginning of the twentieth century was such that it was abandoned to its fate soon after its discovery because it did not attract the attention of the persons responsible for it at that time. The way that water has affected the site is the direct consequence of this lack of interest.
From its reappearance during current excavations, TT 209 has become a data source for a number of research perspectives. Among the archaeometric ones, we have begun the register of environmental conditions discussed in this article. The information thus obtained is being used as a basis for efforts to minimize the adverse effects of the removal of wet sediments on the walls of the tomb, and for planning a future conservation programme. These data can also be used as a reference for changes in the conditions of tombs over years, and to propose measures for the excavation and conservation of other monuments of the Theban necropolis that have comparable architectural structures – an open courtyard and underground chambers which, like TT 209, have been exposed to rain or to floodwaters.
Data acquisition instruments and their locations
In order to achieve a low-cost environmental monitoring solution with high resolution and low power consumption, we developed our own data acquisition system (DAS) based on the following basic components (fig. 4):
PIC18F2523 microcontroller by Microchip Technology Inc.; and
1 megabyte of non-volatile flash memory, A25L080 by AMIC Technology.
One of the register instruments.
The original 12-bit resolution of the A/D converter was increased to 16-bit using oversampling techniques. DAS units were created with the technical specifications listed in table 1. The system is programmed to record temperature and relative humidity every 15 minutes.
Data acquisition system (DAS) characterization.
With four ‘C’-size batteries and the scheduled sampling period, the DAS can operate on an ongoing basis for more than seven years, provided that there are no mechanical failures due to external causes. The units were installed at the end of January 2014, and their data are collected during our archaeological campaigns, 6 but the instruments are active year-round.
As a reference for external variations, three instruments were constructed and placed in three different, complementary areas. One DAS unit was placed on the roof of a private house near the Medinet Habu temple, and the other two were installed in underground chambers in TT 209 (see fig. 2). The first of these is in the transverse hall, which is the first chamber behind the entrance door, and the second is in the north-west chamber deep in the interior (fig. 5). The reason for introducing two instruments was to document the differences that human impact had on the environmental conditions, and the attenuation of strong external oscillations of temperature and relative humidity in two parts of the tomb, both when the tomb was being investigated and when it was closed. The entrance to the underground chambers is closed between working seasons. In January 2014 this was done with a wall of stones, and from May 2014, with a door made of metal bars and a grill, complemented with a wall of loose stone. Maintaining a degree of control over airflow into the tomb was deemed critical, and so the wall is low enough to allow air to circulate. Electric fans are used during working periods to compensate for any additional humidity produced, either by the team or through the drying process.
DAS in place, in the north-west chamber.
The conditions inside TT 209 have influenced the survivability of the DAS units. While the one in the transverse hall has weathered the periods between seasons well, the unit in the north-west chamber stopped working between the fourth and fifth seasons. We conclude that it was damaged by the very high relative humidity deep in the tomb. In 2016 they were both replaced with new instruments that have similar characteristics. Their data will be analysed in the future, because the 2017 season in Egypt could not be carried out, and we therefore have not had access to them.
Results
The data provided by the DAS units have been converted into several charts and complementary tables. They are intended to exemplify the variations in temperature and relative humidity between the exterior and interior areas of TT 209, both during short episodes of time and during the annual cycle. In the period analysed for this article, the situation in the two chambers in which the DAS units were installed differed from one another.
The sediments in the transverse hall were gradually excavated. They had been soaked by the last flash floods that had entered the tomb, and so were still damp when work began on the southern half of the sediments during the 2013/2014 season, which was when the DAS units were introduced. By the following campaign, only four months later, the remaining part of the southern half had been removed and the northern half continued to be excavated. Only the final 45 cm were left in the transverse hall at the end of this season, which were removed in 2015 (figs 6a–6c).
Transverse hall during excavation process. 6a: beginning of the season 2013–2014; 6b: season 2014; 6c: season 2015.
There were no changes in the north-west chamber over the period covered by the results analysed in this study. The chamber was covered up to half its height by sediments soaked in the last flood, which were not touched. Its excavation was only undertaken in 2016.
(A) External oscillations and their attenuation inside the tomb
The first set of graphs (1A and 1B, see figs 7 and 8) display the variations in environmental conditions between the exterior and the interior of TT 209. To this end, the data recorded by the three DAS units have been compared. The authors have chosen to represent the records of a very short period, between February and April 2014, which correspond to the months immediately after the data register was started and when only a small volume of sediment had been removed. Environmental conditions at this time were the closest we had to the ‘natural’ situation of the soaked chambers, before our intervention, while the later systematic removal of the sediments changed these conditions. Table 2 shows the mean daily oscillations during this period. There was no human activity in the tomb during the months represented in these graphs.
Graph 1A: Temperature registered by the three instruments. Period: January to March 2014.
Graph 1B: Relative humidity registered by the three instruments. Period: January to March 2014.
Mean values of temperature and relative humidity variation ranges. Period: February to April 2014. Exterior and inner chambers of TT 209.
Δ = variation.
TH = transverse hall.
NWC = north-west chamber.
Graph 1A (fig. 7) presents the temperature. It shows the large thermal amplitude registered by the exterior unit, a consequence of the day–night cycle, and how this variation is drastically reduced in the underground chambers, and particularly in the deepest ones. Thus, while the exterior unit registered a daily amplitude of about 20 °C, in the transverse hall this amplitude was reduced to 2 °C, and in the north-west chamber it was below 0.1 °C. This means that the latter maintains a constant temperature, with negligible variation over the recorded period. The temperature in the innermost chamber coincides with the monthly average recorded by the exterior DAS, and table 3 shows that this trend can be extended to cover the whole year. This is not specific to TT 209 because it has also been demonstrated in caves, 7 and by extension must be true for all the deep hypogea and tombs excavated into the bedrock of Egypt.
Monthly average values of temperature and relative humidity. Period: February 2014 to June 2015. Transverse hall of TT 209.
Graph 1B (fig. 8) shows relative humidity recorded by the three DAS units over the same period. Unlike temperature, the relative humidity increases significantly with depth. There is also a notable reduction in daily variation. The exterior unit shows variations that can reach 30% across the day–night cycle, with fluctuations ranging between 20% and 50% in absolute terms. In the transverse hall these variations are smaller, of around 10%, which oscillate between 55% and 65%. In the north-west chamber the variations are smaller still, around 2%, but the oscillations are above 80% permanent relative humidity. It is also significant that exterior variations are reflected inside the tomb, but however prominent these are, their spread is characterized by a gradual attenuation towards the deeper chambers (see the days around 10 March). In the transverse hall there are several relative humidity drops at the end of February and March, which are a specific situation and may be related to a southerly wind coming through the door and reducing humidity levels. The unit in the north-west chamber also registered a steady increase at the end of April, which is another exceptional situation and could be due to condensation inside the DAS itself, caused by relative humidity when it surpassed 90%.
(B) Annual climate cycle
Graph 2 (fig. 9) shows the exterior temperature and relative humidity for one year. The Egyptian climatic cycle is characteristic of the northern hemisphere, and so has maximums of temperature and minimums of relative humidity in the summer, and the opposite during the winter. With a slight delay and an attenuation of daily and annual variations, this is what would be expected of the registers inside a tomb under stable conditions, without human intervention. It would also be the situation observed in graphs 1A and 1B once extended throughout the year, but circumstances were different in the underground chambers of TT 209 due to archaeological work carried out by MAULL in order to remove the sedimentary deposit.
Graph 2: Annual cycle outside the tomb.
Graphs 3A and 3B show the annual variations inside the transverse hall using data from its DAS, from January 2014 to June 2015. This is the period between the second and fourth excavation seasons, with the third season in the middle of it. Table 3 collects the monthly averages of the data for the yearly cycle.
Graph 3A (fig. 10) shows that the natural cycle of maximum temperature in summer and minimum in January (from data outside the tomb) is maintained in the transverse hall (see, for example, August 2014 and January 2015) with an amplitude of about 7 °C. However, the oscillations are accentuated in the second year, which is a result of the gradual emptying of the chamber. Thus, if the mean temperatures of a certain month are compared over the two consecutive years, a decrease of about 2 °C is observed in the winter months of the second year (for example, between February 2014 and 2015), while in the summer months they seem to rise (see June 2014 and 2015). The effect of archaeological seasons is also observed: the opening of the door and the excavation process during the third campaign (April to June 2014) involved very high oscillations in the daily cycle, which parallels a notable decrease in relative humidity.
Graph 3A: Temperature in the transverse hall. Period: January 2014 to June 2015.
The data presented in graph 3B (fig. 11) and collected in table 3 show that there was a gradual decrease in relative humidity of more than 30% across the documented period: in February 2014 the average was 62.9%, whereas in the same month of 2015 it was 31.7%. This loss of humidity is consistent but was accentuated after the third season, when a door with a grill was installed that made it unnecessary to seal the entrance with a solid wall between working seasons, and which allows improved air circulation towards the interior. Thus, after the third season, the relative humidity in the transverse hall returned to pre-excavation levels, but in the following months showed a significant continuous decrease (fig. 12). This curve can be interpreted as the effect of the walls gradually losing humidity after the removal of the wet sediment.
Graph 3B: Relative humidity in the transverse hall. Period: January 2014 to June 2015.
Graph 4: Evolution of monthly average of temperature (T) and relative humidity (RH) in the transverse hall. Period: January 2014 to June 2015.
Conclusions
Several conclusions can be drawn from the data presented in this article. First, the temperature and relative humidity registers have provided useful information for the future conservation of underground chambers.
It is not certain when the last flash flood entered TT 209, but data collected during excavations have provided chronological limits. An industrial bakery wrapper was found on the surface of the north-east chamber, with the year 1995 written on it. It could not be determined whether this referred to its production or expiration date but, if the latter, it would have been produced in 1994 or even earlier. It does, however, provide a terminus ante quem for the flood that deposited sediments in the tomb. S. W. Cross notes that heavy rains fell in the Valley of the Kings in October 1994, October 2001 and January 2008. 8 Only the rain that fell on the first date has been reported in the literature, 9 and the inhabitants of Qurna remember it as having produced the last high flash flood in the area near TT 209. 10 An objection to the most recent date is that our first visit to the site was at the beginning of February 2008 and there was no sign of a recent flood in the bed of the wadi. As such, even though any of these three rains could have left water in the basin of the Wadi Hatasun, it is most likely the first one – and less probably the second – that dragged the most recent material into the tomb, and our first season was probably carried out 17 years after the final flood event.
The data collected by the DAS units in the first months after their installation may be a close representation of the situation endured by TT 209 for centuries, when it was full of sediments and was soaked by floodwaters after periodic rainfall on the Theban Mountain.
The emptying of the tomb during the excavation process has had both negative and positive effects on its conservation. We do not take into account the procurement of historical information, which is obviously relevant. The most positive aspect is that excavation has reduced the overall level of relative humidity, since the saturated fill has been removed and the walls are slowly drying out. This has reduced the risk of chemical degradation of the rock following prolonged exposure to wet sediments that dry out slowly, as well as the risk of biodeterioration to the surfaces of the walls due to the proliferation of fungi or bacteria that thrive in a warm and highly humid environment. On the negative side, the removal of sediments has increased humidity variability in the interior, a reflection of external variability to which the transverse hall is more vulnerable now that it is empty. To minimize risk, our current solution is to rebuild a low, loose stone wall at the end of every season in front of the grilled door, which reduces exposure to sunlight and heat but allows air to circulate.
It is important to note that despite the years since the last flood, the sediments in the inner chambers were still saturated and the relative humidity was above 80%. When the waterlogged strata in the north-west chamber were excavated in 2016 the relative humidity in the air exceeded 95%. This was the maximum that the DAS instruments could accurately measure, and the percentage could have been even higher. These levels of humidity can be extrapolated to other tombs of the Theban necropolis that have been exposed to flash floods and contain sediments, and have not yet been excavated. Flash flood sediments must be identified before work begins so that proper excavation and conservation programmes can be planned.
Second, the data show limited environmental consequences for the conservation of inner tomb chambers during archaeological seasons.
Variations in the environmental conditions caused by the presence of researchers and local workers during archaeological seasons are significant, but do not pose a risk to the conservation of the tomb as they are of short duration and their effects are clearly below those of natural annual variations. Temperature oscillations in TT 209 did not exceed 5 °C during working days, which is well below the annual winter–summer cycle. Even the significant drying recorded during the third season was temporary; in the following year the chamber already held average levels of relative humidity that were lower than those registered during our previous month and a half of excavation.
Third, the environmental conditions inside tombs used as houses in the West Bank have been recognized.
The reasons for the permanent transfer of some Qurnawi families from their original village around Sethos I’s Mansion of Millions of Years to the necropolis must have been numerous: protection in times of insecurity, visibility over the plain, distance from the annual inundation of the Nile, and, already in the twentieth century, closeness to visitors to the necropolis, to whom they provided a variety of services. 11 Comfort during high temperatures in the summer must also be included among these reasons. At the time of their first permanent occupation, during the nineteenth century, they built no freestanding houses, but rather adapted the inner chambers of the tombs by building mudbrick walls. 12 The environmental records obtained in TT 209 provide data on temperature and – less pertinent in this case – relative humidity that can be extrapolated to those first occupied tombs. The temperatures recorded in the transverse hall of TT 209, less extreme than external ones, would be similar to those of the first chamber of any inhabited tomb, and the year-round stable temperature of 28 °C in the north-west chamber of TT 209 must be comparable to temperature in all the other deeper chambers.
Footnotes
Acknowledgements
We express our deepest gratitude to the sponsors of the MAULL, mentioned in the funding acknowledgement. We thank Lucía Clayton Martínez and R. Gareth Roberts for their corrections of this article’s English language.
Funding
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article. The fifth season of the MAULL was funded by the Fundación Palarq, Barcelona, and the Consejería de Patrimonio Cultural [Cultural Heritage Council] of the Canarian Government. Additionally, we received funds from the Association Isfet and private donors.
1.
Text in J. Thompson, Wonderful Things: A History of Egyptology. 1: From Antiquity to 1881 (Cairo, 2015), 153.
2.
The name of the owner cited in bibliography, Seremhatrekhyt (see PM I.12, 306) is erroneous. This was one of his titles, not his name. On the several possible readings of the name, see M. Á. Molinero Polo, ‘TT 209: Objectives of the Project dos cero nueve and Name of the Tomb Owner’, Trabajos de Egiptología. Papers on Ancient Egypt 7 (2016), 123–8.
3.
M. Á. Molinero Polo, C. M. Hernández Gómez, H. Mohamed Ali, S. Bakhit Abd el-Hafez, D. M. Méndez Rodríguez, F. Guerra Librero, J. C. García Ávila, Z. Barahona Mendieta, J. M. Barrios Mufrege, L. Díaz Iglesias Llanos, and P. Coll Tabanera, ‘The Courtyard of TT 209 (Areas C1 and C2). Seasons 2012 to 2014’, Trabajos de Egiptología. Papers on Ancient Egypt 8 (2017), 268–9.
4.
About objects as active agents of the research process and not only passive subjects, i.e. the notion of active material culture, see, among many other examples: M. Shanks, ‘The Life of an Artifact in an Interpretative Archaeology’, Fennoscandia archaeological 15 (1998), 15–30; J. Hoskins, ‘Agency, Biography and Objects’, in C. Tilley, W. Keane, S. Küchler, M. Rowlands, and P. Spyer (eds), Handbook of Material Culture (London, 2005), 74–84. The actor-network theory has been developed by sociologists such as M. Callon, B. Latour and J. Law. A selection of their works can be read in M. Domènech and F. Tirado (eds), Sociología simétrica (Barcelona, 1998).
5.
Recent anthropological and historiographic theory emphasizes variations in the perspectives that different generations have held for objects, how artefacts continuously absorb new meanings according to the societies that use or conserve them, or how things tell the stories of people’s lives. See, for example, C. Gosden and Y. Marshall, ‘The Cultural Biography of Objects’, World Archaeology 31/2 (1999), 169–78; and, on a more popular level, the multi-platform BBC and British Museum project, N. McGregor, A History of the World in 100 Objects (London, 2010).
6.
The dates of the archaeological seasons since the introduction of the DAS units are as follows. Second season: 18 January to 25 January 2014; third season: 30 April to 9 June 2014; fourth season: 11 June to 23 July 2015; fifth season: 19 July 2016 to 10 August 2016.
7.
G. Badino, ‘Cave Temperatures and Global Climatic Change’, International Journal of Speleology 33:1 (2004), 109–10.
8.
S. W. Cross, ‘The Hydrology of the Valley of the Kings’, JEA 94 (2008), 303–10, n. 7.
9.
L. P. Brock, ‘The Theban Flood of 1994: Ancient Antecedents and the Case of KV55’, Varia Aegyptiaca 11:1 (1996), 1–16; Ch. Leblanc, ‘Thebes et les pluies torrentielles. A propos de mw n pt’, Memnonia 6 (1995), 197–214, figs 1–
and pls xxxvii–xxxix.
10.
Personal communication with Eiz el Din, Director of the Middle Area of the Necropolis, February 2019.
11.
K. van der Spek, The Modern Neighbors of Tutankhamun. History, Life, and Work in the Villages of the Theban West Bank (Cairo, 2011), 61–71.