arizona state university    biggest clusters of hot plumes.read    blob regions    blobs    clumps of dense rock    cold currents    colder rock    core-mantle boundary.to map    deep interior    different times    early planet’s greatest cataclysm    earth scientists    echoes of earthquakes    ed garnero    edges of the blobs    emperor chain    enough material    evolution of the earth    fixed mantle plume    harvard researcher adam dziewonski    highest points    hot spot    hot-blob regions    large low-shear-velocity provinces    largest things    longer history    main structures    mantle    map of earth    opposing camp    past year    planet’s molten iron core    plate tectonics    plumes    recent years    rest of the earth    rocky mantle    scientists    similar pattern    smaller islands    stretch of islands    surface world    tectonic plate    tectonic plates    thermochemical piles    university of maryland    unknown forms    vague outlines    volcanic hot spots    warm regions