Initial Evaluation Of The Effectiveness Of
Mr. Shan R. Shanmugasundaram's
Sun Shadow Deviation Measurement Based
Earthquake Forecasting Procedure

And It’s Significance to Earth Science,
Geophysics & Seismology



Chen I-wan, Advisor
Committee of Natural Hazards Prediction
of the China Geophysics Society



(1) The Sun Shadow Deviation observation based earthquake forecasting technology being discussed in this report might enable us to make significant advances in our understanding of Earth science, geophysics, and seismology.  (2) This technology would also be so inexpensive and easy to use that it might help to enable people living in remote villages to forecast earthquakes. (3) The Sun Shadow Deviation observatory described in this report would also be ideal as teaching aids in schools everywhere including in technically advanced countries, enabling children and young students to acquire an important and interesting understanding of the Earth and knowledge of Earth science.


(1) To describe this technology. (2) To present some preliminary data evaluation results. (3) To request comments on both what is being discussed in the report and on the original data.


Some 387 earthquake predictions were made during July 24 to Oct. 18, 2003.  With 37.2% of the predictions the expected earthquake occurred within plus or minus 3 days of the predicted dates, plus or minus 3 latitude and 3 longitude degrees of the predicted latitude and longitude, and plus or minus 1 magnitude unit of the predicted magnitude. However, under a tighter scale, with 22.5% of the predictions the expected earthquake occurred within plus or minus 2 days of the predicted dates, plus or minus 2 latitude and 2 longitude degrees of the predicted latitude and longitude, and plus or minus 0.5 magnitude unit of the predicted magnitude. For reasons which will be discussed in this report I have concluded that PROPOSED: statements (1) & (2) & (3) are all correct.

My Earthquake Forecasting Background

I am a British - Chinese business consultant, born in Oxford, England, who has been living, studying and working in China since 1950. As a result of events that occurred in 1990 I developed a strong interest in the investigation of a variety of forecasting technologies which were developed in China for earthquake (EQ) prediction and medium/long-term weather forecasting.

During the past three years I have been doing an extensive amount of work in this area myself and also assisting a number of EQ forecasters and medium/long-term weather forecasters in China. I helped several EQ forecasters both attend and present technical papers at the Natural Hazard sessions of the European Geophysics Society 2002 Annual Assembly, Nice in April of 2002. And in connection with those efforts, in May of 2002 I had the honor of being appointed by the China Geophysics Society to be an Advisor to the Committee of Natural Hazards Prediction of the China Geophysics Society. I also eventually became a member of both the European Geophysics Society and the American Geophysics Union.

Shan and his Sun Shadow Deviation (SSD) Observation Based EQ Predictions

In July of 2003, an American EQ forecaster/researcher who frequently corresponds with people using the initials E.D.G. ( Website: http://www.freewebz.com/eq-forecasting/90-03. html), told me about an interesting website in India:  http://EQ.itgo.com/today.htm

Shortly thereafter I began communicating with the Web site’s owner, Mr. Shan, R. Shanmugasundaram and became familiar with his Sun Shadow Deviation measurement based earthquake forecasting procedure. Shan who is aged 46 lives in Coimbatore, Tamilnadu, South India. He is a physics graduate and a ham radio operator who has been working in a private sector bank for the last 25 years. But he has always had an interest in technical subjects such as space science, wireless communication and geology.

Shan has conducted consistent observations of SSD for eight years since 1996. His observatory, located about 11N 77E, is basically a large Sundial that he built himself. He tracks the path of the sun shadow moving over one of the walls (facing east) of his own house. This procedure is one of mankind’s most ancient and simplest astronomy observation techniques.

The "normal path" of the sun shadow location on the wall measured at the same time each day forms a fairly straight line. However, after careful observation Shan discovered that the actual sun shadow path often deviates from that straight line. At times it will move to the right side of the line and at other times to the left. Additionally, the amount of deviation will be different at different times of the day.

Shan also discovered that these deviations from that straight line could be effectively compared with records of past deviations observed when EQs occurred within plus or minus 90 longitude degrees from his observation station. And he began to use that information to post daily EQ forecasts nearly every day for EQs >=Ms4.0 to his Website. 

Parameters Included in Shan’s Daily EQ forecasts 

Ø      Name of the location, it’s latitude and longitude

Ø     Expected magnitude (Ms)

Ø     Expected time window:

An example of Shan’s EQ forecast posted on his website dated Aug. 15, 2003:

UPDATED 15th AUGUST 2003 - 09.45 IST



Around 5M quake over

HINDU KUSH REGION (36.62N 71.17E) - ANDAMAN ISLANDS (12.14N 93.52E)


EAST COAST OF KAMCHATKA (51.26N 158.87E) - SUMBA REGION (9.95S 119.13E)

BANDA SEA (7.4S 128.4E) - IRIAN JAYA, INDONESIA (1.6S 134.3E)


within 48 to 180 hours from 10 AM IST on 14th August 2003.  

Dual Purpose Evaluation:

-- The Practical Value of Shan’s EQ Prediction

-- The Scientific Significance of the Sun Shadow Deviation (SSD)

Based on my knowledge and initial study of Shan’s SSD observation work I felt that the SSDs observed by him could in theory be associated with one or both of two phenomena:

-- Temporary tilt of the local area/crust

-- Temporary shift - tilting in the Earth's North – South Pole rotation axis

I felt that if Shan’s SSD based EQ predictions had a fairly high success rate with EQs occurring on the Indian side of the Earth where he lives, then this would indicate that what he is observing is linked with shifts – tilting in the Earth’s North – South Pole rotation axis as the Earth rotates around that axis each day and as the Earth – Moon system revolves around the Sun each year. And it is my belief that if this can be shown to be the case then this information –Shan’s long-term observation of SSD- could be proved to have made great contribution to our further understanding of Earth science, geophysics, seismology and the science of earthquake forecasting.

Assuming that this is the case I wish to stress that to the best of my knowledge these relationships between SSD, the temporary shift – tilting in the Earth’s North – South Pole rotation axis, and EQ locations, magnitudes, and occurrence dates have not been recognized by today’s Earth science researchers, geophysicists, seismologists, or any other researcher other than Shan.

In an effort to determine what the value of Shan’s forecasting method might be for both predicting EQs and expanding our knowledge of geophysics on July 24, 2003 I started evaluating all of the daily forecasts for EQs with a magnitude greater than Ms4.0 which were posted to his website http://EQ.itgo.com/today.htm, against EQs >/=Ms4.0 reported by NEIC, EMSC and RedPuma.  

[ Evaluation Report : Part 2 || Part 3 || Part 4 ]

Please send your comments and suggestions to Chen I-wan <<>> Shan









Top of this page