River deltas: Valuable and under threat

The livelihoods of millions of people who live in river deltas, among the world's most productive lands, are at risk. Created where large rivers meet the ocean and deposit their natural sediment load, river deltas are often ...

Salt causes chalk cliffs to collapse

Salt plays a greater role in undermining chalk cliffs than previously thought, say scientists. Until recently, if a chalk cliff collapsed it was blamed on waves eroding its base, or the chalk weakening as it became saturated ...

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