Which phenomenon causes melting in the mantle wedge above a subducting oceanic plate?

💡 Explanation

When an oceanic plate subducts, hydration melting occurs because hydrous minerals in the slab release water into the overlying mantle wedge, lowering its melting point. Therefore hydration causes melting, rather than decompression, friction, or decay which contribute less or operate through separate mechanisms.

• Which climatic shift occurs when weakened trade winds disrupt equatorial ocean currents during strong El Niño events?
• Which outcome occurs when increased rainfall intensifies chemical weathering within granite?
• Which phenomenon causes nutrient enrichment in surface waters during coastal upwelling?
• Which climatic response increases when weakened trade winds reduce upwelling during an El Niño event?
• Which outcome increases when prolonged drought accelerates deflation?
• Which risk increases when earthquake-induced liquefaction occurs beneath a coastal levee?