Geologists are watching them – Are Ants sensitive to Earthquakes?
Red wood ants settle on active gas-permeable strike-slip fault systems for they provide ideal nest locations. Therefore, the point is, whether geological problems can be solved by watching the ants’ behaviour. One of the unsolved problems in geological research is the prediction of earthquakes. In the “Laacher See Region” (Eastern Eifel), low magnitude earthquakes (below magnitude 2) accumulate in the last years.
Therefore, a research project started in this region monitoring a red wood ant nest 24 hours a day. The objective is to investigate, if sensitive hints coming from fauna are useful earthquakes precursors, which could work besides the worldwide-operated technical equipment.
Red wood ants provide great advantages: Compared to other species, which are found to be sensitive for earthquakes and described in literature so far, red wood ants are stationary and can be watched around-the-clock. Furthermore, they are living directly on top of the “information bearing channel” arising from the deep crust and are having a close contact to the fault system. A very special advantage of red wood ants is their high sensitivity for changes of the environment. They can detect and determine CO2-concentrations – a precondition for an optimized regulation of oxygen concentration within their nest.
Additionally, CO2 arises from the deep crust. The gas amount and its composition can vary just before and after an earthquake happens. This is supposed to cause earthquake response by the ants.
Red wood ants are also able to react on minor changes of temperature rises. Probably they are also able to record acoustic, electro-magnetic and micro-seismic signals coming from the deep crust.
An available infrastructure is the pre-requisite for watching red wood ants all over the year. Because such an infrastructure is not given in the natural habitat of a forest, a radio appeal was started in summer 2009. The objective was to find a combination of a red wood ant nest with electricity supply on a real estate.
In response to the radio appeal, an optimal location with a red wood ant nest (F. pratensis) was found. Since September 1, this ant nest is monitored around-the clock by a high-resolution camera.
The produced digital amount of data is enormously: 40 GB per day. These data are stored on a Network-Attached-Storage-System (NAS) on-site.
At present, we work at an on-line evaluation and at the improvement of the data handling.
The data are stored on a hard disc system for the further workflow.
Evaluation
At present time, only the ant activity on top of the nest, which is captured by the camera, is evaluated. One or two persons, who examine the activity visually and subjectively, perform the evaluation. On critical days (see below) a third neutral person performs an additional evaluation. In the long run, a software-based evaluation is planned. Before that, we have to meet the challenge to solve the technical problem of the low contrast of little dark ants on brown-coloured nest-building material. The ants activity on top of the nest is divided into 6 classes, from 0 (no activity) to 6 (extreme activity).
First results
Evaluations of the first five weeks show that red wood ants have daily routine. Oversimplified, they show a daily routine which can be characterized by one increasing wave of activity at daybreak (from 7:30 h until approximately 11:00 h.), two waves with high activity peaks between 11:00 h and 18:00 h and a decaying wave showing decreasing activity at evening hours.
From midnight until approximately 7:30 a.m., all ants are staying within the nest (level 0 activity). After the wake-up at approximately 7:30 h, they open their exits and air the nest for approximately 1.5 hours. From 11:00 h up to 13:00 h and from 15:30 until 17:00 h they show a high activity (level 5-6 activity). From 17:00 h their activity calms down and all ants go back into the nest again (Fig. from 05.09. – 09.09., 18.09., 22.09., 23.09., 25.09. – 28.09.).
On 10 September 2009, a magnitude 3.2 earthquake happened about 30 km away from the nest location. The ant activity before and after this earthquake, was unusually. From midnight that day up to 10:00 h the following day (11 September 2009) the ants did not go back into their nest but stayed on top of the nest at a medium level of activity (3-4). They started their daily routine not until 10:00 a.m. the next day.
Besides the visual evaluation, further aspects such as location’s earthtides or climate data have to be taken into account for interpretation.
The first very interesting results show, that ants have a very identifiable daily routine (see average daily routine figure built from and smoothed out of the days 06.09. and 25.09. till 27.09.), which is changed obviously by secondary influences. The example of 10 September 2009 shows that there might be also earthquake precursors as possible influences. The meteorological situation is also decisive for the ants` behaviour. The 25 to 27 September 2009 show similiar meteorological situations compared to 10 September 2009. On these days, the ants` activity shows a normal daily routine. Therefore, the climatic influence seems to be irrelevant for this abnormality on 10 September 2009. In addition, the changes of earthtides show no feature, which could act as an indicator. On September 12, 13, 16 and 29 low magnitude earthquakes hit the “Neuwieder Becken Region”. These days show partly same activities just before of an earthquake. It is obvious that the recovery is always oppressed.
During the monitoring, several high magnitude earthquakes happened in the Far East. The quake waves were registered by German seismological monitoring stations close to the ant monitoring station within some 10 minutes. Whether these quake waves lead to changes within the crust is not clarified yet.
Another question is, if red wood ants are able to register something of these possible changes within the crust. The registration of precursor phenomena by ants from this distance can be excluded. We put the far distance earthquakes (M > 6.0) on our figures as an additional information. Those days with M 6.0 earthquakes show abnormal daily routines in ants’ activity in many cases.
As always, there are exceptions. These are the days from 19 to 21 September 2009. Those days do not show any earthquakes in the “Neuwieder Becken Region” nor far distance earthquakes with high magnitudes.
A still dissatisfactory explanation is that we detect precursor phenomena of earthquakes in our figures, but a real quake did not occur. Possible explanations are that stress conditions might not have been high enough to initiate a quake or stress was slowly relieved. Different causes could be detected by comparative measurements.
It has to be clarified, that this is a first step into a new research issue. The challenge is to investigate, if ants show any kind of reaction or behaviour on earthquakes. The first results give us hope to continue our research. Nevertheless, data have to be collected and analyzed for a year at least and not only at one ant monitoring station. Three monitoring stations in the “Neuwieder Becken Region“ would be ideal.
To verify these results, the second location for monitoring ants’ activity is casted about in the “Neuwieder Becken Region” (Westerwald), at present.
If the ants` reaction and behaviour in the run-up to earthquakes would be significant and reproducible, an ant-monitoring network – similar to meteorological monitoring stations – has to be taken into account, which could provide the possibility of earthquake prediction with an adequate lead time.
The objectives within the next months are, besides the installation of a second station, to identify daily routines of ants as much as possible. For this, the winter months rank among with snow, frost, hail and dew. In addition, springtime will be very interesting to us with the sunbaths of ants, influences of rainfall and nuptial flights. In summer time, heat and intense rain might influence the ants` behaviour. Additionally, disturbances of the nest caused by bigger animals, e. g. birds have to be analyzed. Only the knowledge of the standardized daily routine of ants` behaviour will allow realistic evaluating of additional influences as earthquakes.
What are our future plans?
Geophysical investigations and geochemical analyses of geogases should be carried out in parallel to the around-the-clock observation.
- Nano-seismologic investigation detecting fault systems and analyzing the effects of far distance earthquakes
- Monitoring of geogas to survey the influences of earthquakes on potential gas paths
- Current measurements to estimate the influences of piezoelectric fields within quartz-filled fault zones (before an earthquake or in the course of possible effects of earthtides)
We will put the data gained every month promptly on the internet, to initiate a broad discussion by scientists.
