Chemical weathering is caused by rain water reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts. These reactions occur particularly when the water is slightly acidic.
The 2004 Sumatra Earthquake and Indian Ocean Tsunami gave us a vivid description of menace of major tsunamis. It also suggested that tsunami science and engineering were inevitable to save human society, industries, and natural environment.
An answer can be found in Japan. Japan is the country the most frequently hit by tsunamis in the world. The experiences are well documented and are continued as the local legends. In 1896, the tsunami science started when the Meiji Great Sanriku Tsunami claimed 22,000 lives. An idea of comprehensive countermeasures was officially introduced after the 1933 Showa Great Sanriku Tsunami. The major works taken after this tsunami, however, were the relocation of dwelling houses to high ground and tsunami forecasting that started in 1941. The 1960 Chilean Tsunami opened the way to the tsunami engineering by elaborating coastal structures for tsunami defense. The 1983 Japan Sea Earthquake Tsunami that occurred during a fine daytime cleared the veil of actual tsunamis. The 1993 Hokkaido Nansei-Oki Earthquake Tsunami led to the practical comprehensive tsunami disaster prevention used at present, in which three components, defense structures, tsunami-resistant town development and evacuation based on warning are combined.
The present paper briefs the history of tsunami research in Japan that supports countermeasures.
As any other ancient civilization, the Sumerians were traders as well. And they had a few good reasons to do this.
Because they traded, their trading partners were less likely to attack them, because it would hurt their economy as well. Furthermore, they didn't produce everything they needed and traded those goods with goods which they produced too much of.
And lastly, through trade they could also get exotic goods which they would have never gotten otherwise.
For example, pH can have an effect of the state of ionization of acidic or basic amino acids. Acidic amino acids have carboxyl functional groups in their side chains. Basic amino acids have amine functional groups in their side chains. If the state of ionization of amino acids in a protein is altered then the ionic bonds that help to determine the 3-D shape of the protein can be altered. This can lead to altered protein recognition or an enzyme might become inactive.
Changes in pH may not only affect the shape of an enzyme but it may also change the shape or charge properties of the substrate so that either the substrate connot bind to the active site or it cannot undergo catalysis.
In geneal enzyme have a pH optimum. However the optimum is not the same for each enzyme.
Nuclear envelope is the answer