New Life Amid Death

As the human loss from last week’s earthquake-triggered tsunami reaches ever more unfathomable numbers on land, unseen transformations in the shallowest coastal waters and the depths of the Indian Ocean are likely wreaking environmental havoc in ways that may take years, or even decades, to discover.

Avalanches on the ocean floor and swirling currents of sediment could kill vast swaths of deep-dwelling marine life. Other natural forces might devastate fish populations and destroy coral reefs, tide pools and low-lying forests. Conservationists make it their goal to keep the environment in stasis, to ward off the destruction of habitat by mankind, but the Earth -- through forces far more powerful -- shows that change is part of its nature.

And always has been. Nearly 250 years after the 8.5-magnitude Lisbon earthquake and tsunami of 1755 killed more than 60,000 people -- also in an area where seismic upheaval is rare -- scientists are only now beginning to learn its effect on nature as well as man. The earthquake under the Atlantic triggered an underwater avalanche. This created a massive current carrying loads of sediment believed to have smothered most of the life across hundreds of miles of the ocean floor.

Similar forces may be at work after the Asian earthquake, perhaps on a far greater scale, oceanographers say. But at such great depths, the effect will be difficult to measure.

Damage along the coast will be more obvious -- and have more noticeable effects on humans. Powerful ocean surges probably uprooted mangrove stands, which provide a woody underwater nursery for juvenile fish and shrimp. The effect on fish populations could be profound.

In areas lifted by the earthquake, tide pools and wetlands may now be beyond the reach of high tides. Or the reverse may have occurred. The 9.2-magnitude Alaskan earthquake of 1964 sank a section of coastal forest to just below sea level, marking it for destruction by salt water.

Scientists take a view that can be much too long for human comfort: Such changes can help the environment in unforeseen ways. An underwater avalanche can move nutrients to previously barren areas, fostering new life. The ash left behind by volcanic eruption provides fertile soil for plant growth. Some of the most beautiful flowers in Southern California’s hills show themselves only after a destructive wildfire.

Even colossal extinction events -- such as the one 251 million years ago that wiped out 95% of all marine species and 70% of land species -- make way for other species to thrive. Some geologists and environmental scientists theorize that without natural catastrophic events making such global shifts, the Earth would be a dead planet. Even as these disasters crush lives and hopes in a scope beyond comprehension, they make it possible for life to go on.