Reclaimed land does not have one fixed earthquake magnitude it can “withstand.” Its safety depends much more on soil compaction, foundation design, groundwater, and how far the quake is from the site than on magnitude alone.

What the evidence suggests

  • On reclaimed land, liquefaction is often the main hazard: the ground can behave more like a fluid during shaking, which can damage roads, utilities, and building foundations.
  • One report on Mumbai said reclaimed areas were more prone to liquefaction in earthquakes of magnitude 6 and above , with some locations liquefying faster as shaking increased.
  • Another article noted that in severe events, reclaimed shoreline areas may suffer the greatest damage , and that some structures in the wider region may not withstand a magnitude 7.2 quake.
  • At the same time, reclaimed-land buildings are not automatically unsafe; well-designed foundations and flexible joints can help them perform better during distant tremors.

Practical takeaway

A safer way to think about it is:

  • Magnitude 5 to 6: may already cause noticeable shaking and ground problems on weak reclaimed soil.
  • Magnitude 6 to 7+: can become serious for reclaimed areas, especially if the fill is loose or water-saturated.
  • Above that: damage risk rises sharply, but actual performance still depends on local ground conditions and engineering, not magnitude alone.

Simple answer

If you want a plain-language estimate, reclaimed land can be vulnerable even in a moderate quake around magnitude 6 , and a stronger quake in the 7 range can be very dangerous unless the site and buildings were specifically engineered for seismic and liquefaction risk.

Bottom line

There is no universal “reclaimed land can handle X magnitude” number. The real question is whether the land was properly compacted and whether the buildings were designed for earthquake and liquefaction risk.