Let There Be a Famine in the Land

[Page 305]Abstract: The drought recorded in Helaman 11 is probably the only dated, climate-related event in the entire Book of Mormon that could have left a “signature” detectable over 2,000 years after it occurred. Typical methods to detect this kind of event using dendrochronology (the study of tree rings) or sediment cores from lake beds either do not go back far enough in time or are not of high enough resolution to detect the event described in Helaman 11. However, over the last 15 to 20 years, various researchers have turned to analyzing stalagmites collected from caves to reproduce the precipitation history of a given area. These analysis methods are now producing results approaching the 1–year resolution of dendrochronology, with 2 sigma (95%) dating accuracies on the order of a decade. There is an ongoing debate with regard to where the events in the Book of Mormon took place. One of the proposed areas is Mesoamerica, specifically in southern Mexico and Guatemala. This paper will test the hypothesis that the drought described in the Book of Helaman took place in Mesoamerica using the results of precipitation histories derived from the analysis of three stalagmites compared to determine if there is evidence that a drought took place in the expected time frame and with the expected duration.

The Book of Mormon records that the prophet Nephi, son of Helaman, asked God to cause a famine in the land with the hope that it would end the destruction and wickedness caused by a war with the Gaddianton robbers[1] (Helaman 11:2, 10). This event is unique in the Book of Mormon because it may be the only recorded event that can be dated within an accuracy of a few years and that might have left an [Page 306]imprint or signature that could be detected today, over 2,000 years after it took place. This famine had the following characteristics:

- Three- to 3.5-year duration. It began during the 73rd year of the reign of the judges (Helaman 11:2–5), 19 “Book of Mormon years” before the birth of Christ (3 Nephi 1:4– 13). It ended during the 76th year of the reign of the judges (Helaman 11:17), 16 “Book of Mormon years” before the birth of Christ.

- Involved a relatively large geographic area that extended outside of Nephite lands (Helaman 11:6).

- Caused primarily by a lack of rain, not some other reason like war, plant diseases, or locusts, for example (Helaman 11:6, 13, 17).

- Severe enough that it stopped the war, and “they did perish by the thousands in the more wicked parts of the land” (Helaman 11:6).

Dating this event in terms of Book of Mormon chronology depends on what year Christ was born. There are differing opinions on this subject, but the proposed dates are generally within a range of about 4–5 years. A few of the proposed dates are described below:

- Doctrine and Covenants 20:1 indicates a date of 6 April 1 BC for the birth of Christ. (There is no year 0, so if he were born on 6 April 1 BC, he would have been 1 year old on 6 April 1 AD, and his birth could also be specified as being 0 AD)

- Spackman argues, based on historical evidence, that Lehi must have left Jerusalem sometime between the spring of 588 and the spring of 587 BC[2] He also accepts scriptural and historical sources that indicate Jesus Christ was born in the spring of 5 BC, but his claim is that the only way to fit 600 years from time Lehi left Jerusalem to this birth of Christ is to assume the Nephites used a 12–moon lunar calendar so their years were shorter than present-day solar years.

- Pratt compares the evidence for several dates that have [Page 307]been proposed for Christ’s birth.[3] He argues, based on some of the same historical evidence as Spackman concerning events before and after the Biblical account of the birth of Christ, that Christ was born around the time of the Passover, about 6–9 April, 1 BC

- Humphries compares the Biblical account and Persian customs/traditions with historic astronomical and other evidence[4] to propose that the star of Bethlehem was a comet documented in Chinese records and that the date of the birth of Christ was sometime during the period 13–27 April 5 BC, which also coincides with Passover of that year.

- Dunn indicates, “Jesus himself is generally reckoned to have been born some time before the death of Herod the Great in 4 BCe. A date between 6 BCe and 4 BCe would accord with such historical information as Matthew’s birth narrative assumes (Matthew 2.16) and with the tradition of Luke 3.23 that Jesus was ‘about thirty years age’ in the fifteenth year of Tiberius Caesar (Luke 3.1), reckoned as 27 or 28 CE.”[5]

Many other sources, both Latter-day Saint and non-Latter-day Saint, could be cited, but all sources the author is aware of fall within the range of years defined by the sources cited above. This range produces a corresponding range for the years when the drought described in Helaman would have occurred. All that is necessary is to determine whether or not this range of years for the drought event overlaps the range of years of drought events in geographic areas of interest defined from other sources.

These proposed dates for the birth of Christ generate a range of years when the beginning of the drought could have taken place. If the spring of 6 BC is used as the date Christ was born and solar years are assumed, the beginning of the drought could have been as early as the spring of 25 BC If the spring of 1 BC is used as the date of the birth of Christ and lunar years are assumed, the beginning of the drought (converted to current the modern calendar) could have been as late as the fall of 20 BC [Page 308](using 12×19 lunar cycles and a lunar cycle = 29.53 days2). This drought can therefore be described as starting any time from 25 BC through 20 BC inclusive, having a duration of 3 to 3.5 years and being severe enough that most crops could not grow because of the lack of precipitation.

To resolve the confusion of the calendar schemes (i.e., BCE/CE, BC/ AD), the remainder of this paper will use the convention of +/- AD to indicate years, since this designation is familiar to most people and avoids the issue of the missing year 0 in the BC/AD convention, especially when doing associated math. So, the drought can be described as starting as early as the spring of -24 AD and as late as the fall of -19 AD.

Detecting a drought as short as 3 to 3.5 years over 2,000 years ago presents difficult challenges. The method used to reconstruct the precipitation history needs a resolution on the order of half of the duration of the event being sampled. This means the time between samples of the precipitation history must be about 1.75 years or less. Any approach having a width between samples that is much larger than this value might not detect the event, or even if it does, it would only provide an extremely coarse measure of its duration. Of course, the approach for constructing the precipitation history of some geographic area would also require a way of determining the date or year associated with any given sample and to estimate the accuracy of that association.

Many people are familiar with dendrochronology — the study of tree rings to reconstruct the precipitation history of a given area. The width of the rings can be used to estimate the amount of precipitation by correlating the widths of the rings with known precipitation records in modern times. The earliest portions of the ring width “patterns” from modern trees are then correlated with the most recent patterns of older trees whose life overlapped the modern trees. As long as trees can be identified in a given area whose lives continuously overlapped backward in time, this method can provide a continuous estimate of the precipitation history that extends back before precipitation records were kept. The date associated with each “sample” or tree ring of this precipitation is determined by simply counting the number of tree rings to the desired year in the past. This method of constructing a precipitation history satisfies the requirements for detecting the event in the Book of Helaman since it has a resolution that is ~1 year per sample and can be dated to an accuracy of ~1 year.

[Page 309]One proposed location for the events of the Book of Mormon is the Mesoamerican area, described in great detail by Sorenson.[6] But with regard to the drought described in Helaman and a proposed setting of Mesoamerica, dendochronology is of no use because the oldest tree ring chronologies of the Mesoamerican region do not cover the period of interest, -24 to -19 AD. The oldest dated tree ring in this region comes from central Mexico and begins in AD 771.[7] However, over the last 15–20 years, researchers have been developing methods that have resolutions high enough and dating accurate enough to begin to identify drought events with the characteristics specified in the account recorded in Helaman.[8] In addition, these methods have been used to generate precipitation histories for the Mesoamerican region.[9] This paper will test the hypothesis that the drought described in the Book of Helaman took place in the geographic area known as Mesoamerica using the results of precipitation histories derived from these new sources and methods.

[Page 310]High Resolution Methods of Estimating Precipitation

One of the postulated theories for the demise of the Mayan and other Mesoamerican civilizations has been that it was caused by prolonged droughts on the order of many decades.[10] This has motivated researchers to develop methods for reconstructing the precipitation history of Mesoamerica.[11] Another motivation has been the study of historical climate patterns for the Mesoamerican region as they relate to present climate change and the effect of prolonged conditions like El Niño on weather patterns.[12]

To achieve both high resolution and accurate dating, many researchers have turned to the use of speleothems (cave deposits), such as stalagmites growing in caves in the region of interest.[13] The resolution of the precipitation history obtained from stalagmites is dependent on several factors. One important factor is the rate of growth of the stalagmite.[14] A comparatively short stalagmite that grew over a particular time would have a poorer resolution than a much longer stalagmite that grew over the same period. Another factor affecting resolution is the method used to sample the growth patterns of the stalagmite along its length.[15] For example, curent methods require the stalagmite to be split along its axis. Holes are drilled along the central axis of the stalagmite to provide material for various chemical measurements. The resolution of these methods depends on the width of the drill bit and the spacing between drilled holes. The material removed from a majority of the holes is used to reconstruct the precipitation history, while the material from a smaller subset of holes provides dates (with an associated date accuracy) at the corresponding points along the stalagmite’s axis.[16] These “date” measurements are used to create a “date model” to estimate the date at any arbitrary point in the precipitation history.[17]

These invasive methods and a non-invasive method using light for reconstructing a high-resolution precipitation history from stalagmites [Page 311]are briefly described below. At this point, the reader may want to skip forward to the “Is Mesoamerica ‘the land?’ Published Research Results” section if the following details are not of interest — they are rather technical. However, they are provided to help understand the published results. For in-depth investigation on the subject of using speleothems to reconstruct precipitation history, the textbook Speleothem Science: From Process to Past Environments is available.[18]

Proxy Measurements for Precipitation

Luminescence

The luminescence method[19] uses ultraviolet light to illuminate a narrow (~2 millimeter) region on the central axis of one of the split halves of the stalagmite while recording the luminescence (color) pattern with a camera scanned along its entire length. These patterns are produced by organic acids shown to be dependent on the amount of vegetation produced by the soil in the vicinity of the cave where the stalagmite was formed. Since the amount of vegetation correlates with the amount of precipitation, this luminescence pattern can be used as a proxy for rainfall. Low luminescence (less organic acids) corresponds to periods of lower precipitation, while higher luminescence (more organic acids) corresponds to times with higher precipitation. Since this method is non-invasive (it does not involve drilling), its resolution is dependent only on the rate of growth of the stalagmite. Drilling is still required to produce material for estimating dates/ages along the axis of the stalagmite, but these “age” drill holes are typically spaced much further apart than those drilled for other methods.

[Page 312]Oxygen Isotope Concentration Ratio

The oxygen isotope concentration ratio method[20] measures the concentration of two stable isotopes of oxygen in powders produced from drilling holes at periodic points along the central axis of a split half of the stalagmite. The measured concentration ratio, 18O/16O, is used to determine δ^18O (read delta-O-18, which is a direct proxy for precipitation) by comparing it with the oxygen concentration ratio of a standard, such as Vienna Standard Mean Ocean Water (VSMOW) or Pee Dee Belamnite (PDB), or Vienna Pee Dee Belamnite (VPDB). δ^18O is normally expressed in parts per thousand (

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