Exposed ocean water less lands shore area studies needed regularly at Thiruchendoor Murugan Koyil sea shore

Pasupathi Kumarappan's question 1....

100 feet Thiruchendoor ocean gone away from shores today being full Moon day Vaikasi Visagam....exposing rocks with green moss....this has been a feature happening every Amavasya or Paurnami days....I want to know during Tsunami days how many feet the same Thiruchendoor ocean went away from the shores?

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Grok reply....

**During the 2004 Indian Ocean Tsunami (December 26, 2004), the sea at Thiruchendur (Tiruchendur) receded significantly more than the 100 feet you observed on a full moon/spring tide day—reports indicate around 0.75 miles (about 1,200 meters or roughly 4,000 feet) or up to a full kilometer (about 3,280 feet).**

This matches multiple eyewitness and contemporary accounts from the time. For example:

- One report states: "the sea near the temple receded by a kilometer – people could see there a big crater with rocks visible."

- Another notes the waves "receded away from the Tiruchendur shore temple by 0.75 miles," exposing normally submerged rocks.

### Key Context: Spring Tides vs. Tsunami Drawback

- **Your observation (100 feet / ~30 meters recession)**: This is typical for a pronounced **low spring tide** on full moon (Pournami) or new moon (Amavasya) days like Vaikasi Visagam. The sun and moon's gravitational pulls align, causing higher high tides and lower low tides. On gently sloping beaches like parts of Tamil Nadu's coast, this can expose rocks with green moss and pull the water back noticeably (tens to over 100 feet in some spots). It's a regular tidal phenomenon amplified by the local bathymetry (seabed shape) and lunar cycle.

- **Tsunami (2004 event)**: The initial **drawback** (recession) before the wave arrives is caused by the tsunami's long-wavelength trough pulling water seaward. At Thiruchendur, this was dramatically larger (hundreds of meters to ~1 km) because tsunamis involve massive displaced water volumes from the earthquake. The temple area reportedly saw the sea pull back far enough to spare it direct impact (though nearby areas were hit), with the water later surging but not reaching the main temple structure in the same destructive way.

**Note**: Exact distances vary by exact location along the coast (e.g., right at the temple vs. other spots in Thiruchendur), seabed slope, and reports. The 2004 tsunami caused varying inundation along Tamil Nadu (often 200m–1.5+ km inland in harder-hit areas like Nagapattinam), but the initial recession at Thiruchendur stood out in local accounts.

This is why a sudden, extreme recession (especially not on a normal tide schedule) is a classic **tsunami warning sign**—far beyond regular spring tide behavior. The 100-foot recession you saw aligns with normal enhanced tidal effects, while the tsunami one was orders of magnitude more extreme. If you're there during such events, it's fascinating but always follow local safety advisories for coastal hazards.

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Pasupathi Kumarappan's question 2...

Tsunami period days we all know there was a huge crack or deep gorge happened inside the Indian Ocean near Indonesia Thailand where all these sea water went inside lost (Broken Earth or pilavupatta bhoomi drinking lot of sea water) exposing 1 km area width of open water less land from the Thiruchendoor shores .....the length of this water less exposed lands may not be measured by Institute of Oceanography or Fisheries University or Surveyor General of India....whereas such Scientific studies like measurement of exposed shores....water less areas....during Tsunamis or every Amavasya and Paurnami period is envisaged and recommended by K Pasupathi author of this questions to Grok....can you provide me a report on any IIT or IIM or IISc or MIT or NIT studies regarding the above study of exposed water less shores past 100 years in India Tamilnadu Thiruchendoor?

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Grok reply 2...

**No comprehensive scientific reports or dedicated studies from IIT, IIM, IISc, MIT, NIT, or similar premier institutions specifically focus on systematic measurement of "exposed waterless shores" or tidal recession distances during every Amavasya (new moon) and Paurnami (full moon/spring tide) at Thiruchendur (Tiruchendur) over the past 100 years.**

### Available Relevant Research

Scientific work in the region centers on:

- **2004 Tsunami impacts** — Including initial sea recession (drawback), sediment deposits, beach erosion/accretion, and shoreline changes. Eyewitness and media-linked accounts consistently report recession of ~0.75–1 km (about 2,460–3,280 feet) at the temple area, exposing rocks and a crater-like feature.

- **General coastal morphology, beach profiles, and shoreline dynamics** — These include tidal influences but not routine lunar-cycle monitoring of exposure distances.

Key examples:

- Researchers (e.g., S. Srinivasalu, N. Chandrasekar, S. Saravanan) conducted post-tsunami sediment and geochemistry studies between Tuticorin and Thiruchendur. These involved detailed transects from Chennai to Thiruchendur, mapping tsunami deposits and flow characteristics.

- National Institute of Oceanography (NIO, CSIR) has contributed bathymetry, wave refraction, and littoral sediment transport studies along Tamil Nadu coasts, including areas near Thiruchendur. Beach profile variations (monthly/seasonal) were studied at Thiruchendur and nearby Kanyakumari.

- Multi-decadal shoreline change analyses using remote sensing and DSAS (Digital Shoreline Analysis System) for Thiruchendur Taluk show low to moderate erosion/accretion rates (often 1–4 m/year in some zones), but these focus on long-term trends rather than short-term tidal exposures.

- Post-tsunami beach profile and volume evaluations noted erosion in low-tide zones and shoreline recession (e.g., ~20 m in some Tamil Nadu stretches).

These studies come from Indian researchers affiliated with universities, NIO (Goa), and geological/oceanographic groups — not directly from IIT/IISc/IIM/MIT as primary institutional outputs on this narrow topic.

### Why Limited Specific Studies?

- **Routine tidal exposures** (your 100 ft / ~30 m observation on full moon days) are normal spring tide phenomena driven by lunar-solar alignment. They are well-understood in coastal engineering but rarely warrant dedicated long-term monitoring at a single site unless linked to hazards, erosion, or temple protection.

- **Tsunami drawback** is studied as a one-off extreme event, not routinely compared to spring tides.

- Institutions prioritize broader issues: coastal erosion mitigation, sediment transport, tsunami modeling, and climate impacts. Shore protection reports exist for the Thiruchendur temple (including tide levels and bathymetry).

No evidence of studies explicitly "envisaged/recommended by K Pasupathi" appears in public scientific literature.

### Recommendations

For detailed tidal exposure measurements, local agencies like the Tamil Nadu Fisheries University, Survey of India, or NIO could undertake targeted monitoring (e.g., using tide gauges, GPS transects, or drones during lunar extremes). Your suggestion for systematic study of exposed areas during both tsunamis and regular spring tides is scientifically valuable for coastal hazard awareness, bathymetry updates, and temple/coast management.

If you have specific paper titles, author names, or more details, I can search further. Otherwise, the existing body of work on 2004 tsunami recession and shoreline dynamics provides the closest available data. Always prioritize official coastal safety guidelines during extreme tidal or seismic events.

Pasupathi Kumarappan.
https://notionpress.com/author/83387