MOON SUN SEISMOLOGY
ACADEMIC REFERENCES

MOON SUN FINANCE


This page gives a listing of academic papers published on 
Moon Sun seismology since 2000. For early references on earthquake tidal triggering see ICET.


Relation between Moon Phase and Occurrence of Micro-earthquakes in the Tamba Plateau
 T. IWATA & H. KATAO.
Journal of Geography. Vol 111, No 2. p 248-255. 2002.
Abstract: "In the Tamba Plateau, and earthquake swarm area in the Kinki district, Central Japan, seismicity was activated just after the Hyogo-ken Nanbu(Kobe) Earthquake(Mj7.3), which occurred in an adjacent area in 1995. We found that micro-earthquake activities in the Tamba Plateau corresponded to moon phase. Occurrences of micro-earthquakes increased after a new moon and a full moon during 1995 and 1996. Before 1995, such a correlation could not be found. The present study suggests a possibility that the stress change caused by the Hyogo-ken Nanbu Earthquake made seismicity in the Tamba Plateau sensitive to tidal forces."

Tidal Effects on Tectonic Events
Jeremy D PESICEK. May 2003.
Dept of Physics & Physical Oceanography. University of North Carolina, Wilmington.

Earthquake Clustering Relative to Lunar Phases in Taiwan
Cheng-Homg LIN et al
TAO Vol 14, no 3. pp 289-298. Sep 2003.

Tidal Triggering of Earthquakes in Japan Related to the Regional Tectonic Stress .
Sachiko Tanaka, Masakazu Ohtake, and Haruo Sato .
Dept of Geophysics, Graduate School of Science, Tohoku University, Japan
Earth Planets Space. 56 511-515. 2004.
Abstract: “We observe a correlation between the Earth tide and earthquake occurrence that is closely related to the regional tectonic stress. We investigate the direction of the tidal compressional stress using shallow earthquakes occurring in 100 subregions of Japan for nearly five years. The azimuthal distribution of the compressional stress obtained for the observed earthquake data is compared with that synthesized for random earthquake occurrence. Statistical analysis confirms a significant difference between the observed and random catalogs for 13 subregions, which include the areas where unusual seismic activities took place recently, and where the possibility of future large earthquakes has been argued. For these subregions, earthquakes preferentially occur when the tidal compressional stress is near the dominant direction of P-axes of focal mechanisms obtained in the corresponding subregions. This suggests that the tidal stress may encourage earthquake occurrence when it acts in the direction to increase the regional tectonic stress.”

Earth Tides Can Trigger Shallow Thrust Fault Earthquakes
Elizabeth S COCHRAN, John E VIDALE & Sachiko TANAKA
Science, Vol 306. Nov 12, 2004.
Abstract: "
We show a correlation between the occurrence of shallow, thrust earthquakes and the occurrence of the strongest tides. The rate of earthquakes varies from the background rate by a factor of three with the tidal stress. The highest correlation is found when we assume a coefficient of friction of µ = 0.4 for the crust, although we see good correlation for µ between 0.2 and 0.6. Our results quantify the effect of applied stress on earthquake triggering, a key factor in understanding earthquake nucleation and cascades whereby one earthquake triggers other." 

Planetary Configuration: Implications For Earthquake Prediction
N VENKATANATHAN, N RAJESHWARA RAO et al. 2004 
Department of Applied Geology, University of Madras.

Earthquakes & The Moon: Syzygy Predictions Fail The Test
KENNEDY, Matthew, VIDALE, John E & PARKER, Michael G.
Seismological Research Letters. Sep/Oct 2004. Vol 75. no 5. p 607-612.

Lunisolar Effect on Spring Tides, Earthquakes and Tsunamis
Fritz GACKSTATTER
Journal Coastal Research. Vol 23. Issue 2. Mar 2007.
Abstract: "The periods of the three-body system of Sun-Earth-Moon play an important part in tidal dynamics. In this paper, I deal with extreme proxigean spring tides. To produce these rare and unusually high tides, several tide-raising effects must work together. Hipparcos' lunar evection anomaly is influential. An interesting phenomenon can be observed in that the first extreme proxigean spring tide in the new millennium happened on January 10, 2005, in new moon phase, and half a synodic month earlier, when the Moon was full on December 26, 2004, the Christmas Tsunami was triggered in the Indian Ocean."

Seisoacoutic Emission, Earthquakes and Lunar-Solar Tides
A S BELYAKOV, V S LAVROV & A V NIKOLAEV
MAIK Nauka/Interperiodica. Vol 420. Number 1.  June 2008.

On the reality of the 56-year cycle and the increased probability of large earthquakes for Petropavlovsk-Kamchatskii during the period 2008–2011 according to lunar cyclicity
A A GUSEV. Journal of Volcanology and Seismology. Vol 2. No 6. pp 424-434. Dec 2008.
Abstract: "A 56-year cyclicity in the occurrence of large Kamchatka earthquakes has been previously detected. This is another manifestation of the tendency for the timing of large Kamchatka earthquakes to be synchronized to the cycles related to the period To of rotation of the lunar nodes found by V.A. Shirokov in 1974. He identified cycles of 18.6 years = T
o and 6.2 years = To/3, while the period of the 56-year cycle is 3To. The genuineness of that phenomenon had to be revised in connection with the occurrence of a large (M w = 7.8) earthquake in Kamchatka at the end of 1997, in violation of the 56-year cyclicity. It turned out that, even though the 56-year cycle has become less distinct after the 1997 event, the cyclicity itself has remained statistically significant. A byproduct is an updated forecast of earthquake hazard for Kamchatka. The update is necessary in view of the approaching hazardous period of 2008–2011. It is found that, assuming the validity of these empirical tendencies, the expected rate of large earthquakes off Kamchatka for the period of August 2008 to October 2011 will be four times as high as the long-term mean. We derive the first-ever estimate of future hazard in terms of felt intensity for specified soil conditions (the so-called average soil) at a specified site (the town of Petropavlovsk-Kamchatskii). For these soil conditions, the estimated probability of at least one shock of intensity VII or greater during the period specified above is equal to 0.39 ± 0.15. The expected rate of single events or sets of events with M w ≥ 7.6 in Kamchatka during this period is 0.76 ± 0.25."

Evidence of Earthquake Triggering by The Solid Earth Tides
Laurent METIVIER, et al.
Earth & Planetary Science Letters. Feb 2009. 278. p 370-375. 
Abstract: "Clear evidence for earthquake triggering by the earth tides has remained elusive for more than a century. Using the largest global earthquake catalog available (the NEIC catalog with 442412 events), we observe a clear correlation (with 99% confidence) between the phase of the solid Earth tide and the timing of seismic events: earthquakes occur slightly more often at the time of ground uplift by the Earth tide, i.e. when normal stresses are reduced within the lithosphere. We observe that this phase distribution anomaly is larger for smaller and shallower earthquakes. Although earthquakes in regions with dominantly normal and strike-slip faulting seem to exhibit more tidal triggering than regions dominated by thrust faulting, there is no statistically significant evidence for a focal mechanism-dependence on earthquake triggering. Finally, we show here that it is highly probable that the observed triggering is caused by the solid Earth tide, rather than by loading from the ocean or atmospheric tides. Although an additional impact due to loading from ocean tides is possible and probable, we cannot detect it here because the earthquake database is not sufficiently complete and homogeneous (more small magnitude earthquakes in oceanic areas are needed). Our results are consistent with the idea of a damped sensitivity of earthquake initiation to stress change—an event is slightly more probable (0.5 to 1.0%) when the tidal displacement is maximum, particularly for small and shallow events." 

Tides, Earthquakes, and Volcanoes
Junzo KASAHARA
Science. Vol 297. no 5580. pp 348-349. Jul 19, 2009.
Summary: "Earthquakes and volcanic eruptions are caused primarily by plate tectonics. But as Kasahara explains in his Perspective, several recent studies provide evidence that tidal forces influence earthquakes associated with volcanic activity. This idea was first suggested in the 1930s, but the forces involved were long considered too weak and the evidence too limited. Recent results from the Juan de Fuca Ridge in the Pacific show a particularly clear diurnal pattern attributed to ocean tides."

Tremor-tide Correlations and Near-Lithostatic Pore Pressures at Parkfield
Amanda THOMAS
University of California, Berkeley. Dec 2009
Abstract:
"New observations of tidal triggering of non-volcanic tremor near Parkfield, CA present a unique opportunity to better understand the nature of tremor and the conditions under which it occurs. Here we perform a full tidal analysis to determine the stress orientations and magnitudes that favor tremor generation on the lower-crustal San Andreas fault. Our results show that extremely small shear stress perturbations primarily influence tremor activity levels while much larger normal stress fluctuations and stressing rates have little to no influence. These findings are indicative of near-lithostatic pore pressures in the deep San Andreas fault zone and suggest that low effective normal stresses explain the response of non-volcanic tremor to tidal forcing."

Tidal Triggering of Earthquakes Precursory to the Recent Sumatra Megathrust Earthquakes. 
Sachiko TANAKA National Research Institute for Earth Science & Disaster Prevention, Japan
Geophyisical Research Letters. Jan 21, 2010. doi:10.1029/2009GL041581
Abstract: "I observed tidal triggering of earthquakes precursory to the three giant earthquakes occurring off Sumatra on 26 December 2004 (Mw 9.0), 28 March 2005 (Mw 8.6), and 12 September 2007 (Mw 8.5). I measured the correlation between the Earth tide and earthquake occurrence in and around the focal regions of these megathrust earthquakes. The result of statistical analysis indicates that a high correlation appeared for several to ten years preceding the occurrence of the large earthquakes. The correlation vanished after the main events. The frequency distribution of tidal phase angles in the pre-event period exhibited a peak near the angle where the tidal shear stress is at its maximum to accelerate the fault slip. This implies that the high correlation observed in the pre-seismic stage is not a stochastic chance but is likely a physical consequence of the tidal stress change."
 

EARTH TIDES AND EARTHQUAKES
Vinayak G. KOLVANKAR*, Samrudha MORE# and Nisha THAKUR#.
*C/O Computer Division, Bhabha Atomic Research Centre. Mumbai 400085, India.
# Project Trainees from BVMIT CBD Belapur, Mumbai, India.  
New Concepts in Global Tectonics Newsletter. No 57. p 54. Dec 2010.
Abstract: "Earth tides trigger earthquakes, which is an established fact. In this paper we try to find out the characteristics of the earthquake triggering pattern by Earth tides, utilizing over 5 hundred thousand events from NEICUSGS earthquake catalogue for global earthquakes with magnitude range of 2-10. We studied different patterns of the triggered earthquakes for different ranges of periods, magnitudes, depths, latitudes and longitudes. Although different researchers have made similar studies utilizing different regions of the globe with different fault types, we have studied this effect of earthquakes triggered by Earth tides for the entire globe and hence no particular fault type was considered. This study conducted for earthquakes in two different periods (1973 - 1989 and 1990 – 2008) indicates that Earth tides trigger earthquakes at all depths and up to magnitude 5.0. The lateral stresses applied during Earth tides close to full Moon phase are found to be more effective than those stresses of Earth tides during the new Moon phase. However, close to new moon phase, earthquakes of magnitude up to 3.0 and at shallow focus range up to 10 km are triggered directly by the combined pull from Moon and Sun. A study is conducted for one of the high seismicity area utilizing the patterns of earthquakes triggered by Earth tides, obtained for consecutive periods, which provides good idea about the periodical stresses built up prior to major earthquakes. The Earth tide plots for different smaller areas (typically 2000 X 2000 Km) in the high seismicity regions show quick changes. Foreshocks and aftershocks of major events were found to align in a column representing range of Sun-Earth-Moon (SEM) angles. In the aftershocks, this column might continue in the foreshock column or shift to adjacent column or any other column depending on the change in the geometry and orientation of the fault where major earthquake occurs."


ARTICLES

Can the Moon Cause Earthquakes?
John ROACH
National Geographic News. May 23, 2005.

Moon Linked To Earthquakes At Last
New Scientist. Feb 4, 2009.

Sun Moon Trigger San Andreas Tremors, Study
Reuters. Dec 23, 2009.

Moon, Sun Could Help Trigger Powerful Earthquakes.
Asia News Network. Feb 9, 2010.

Great Quake Coming, Feel The Earth Tides
New Scientist. p 16. Feb 27, 2010.