Geophysics - Geo★ Down Under

Unlocking the secrets of the sub-Antarctic underground

Staff from the Australian Antarctic Division are now installing seismometers on the Macquarie island as part of the "Macquarie Ridge in the 3D" project.

Geodynamics

A tight squeeze between tectonic plates

The largest earthquakes occur at subduction zones, where one plate descends beneath another into the underlying mantle, at a convergent plate boundary. Some subduction zones seem to host more large

Geophysics

Chatting about reconstructing 1 billion years of Earth evolution in Geology Bites podcast

This is a transcript of a podcast with Oliver Strimpel from GeologyBites. We chat about the challenges and benefits of reconstructing Earth evolution over a billion years.

Geohazards

Floods And Covid-19 In Timor-Leste Reveal Risks Of Interacting Hazards

Flash floods, landslides, and rising rates of COVID-19 in Timor-Leste show how multiple hazards can interact with deadly consequences.

Geohazards

Flooding And Landsliding In Timor-Leste: Linked Hazards In A Young Mountain Belt

Timor-Leste and Indonesia were battered by tropical cyclone Seroja over the Easter period. Seven days of heavy rain and wind caused severe flooding and landslides.

Geodynamics

East Australian Volcanism – interaction of plumes and subduction remnants

Eastern Australia hosts a wide range of volcanic edifices, ranging from localised outcrops to lava fields and central volcanoes, mostly older in the North, younger in the South. Here we discuss potential controlling mechanisms.

Tectonics

Modelling global precipitation since 250 million years ago

We have developed a novel data-driven approach to reconstruct precipitation patterns through geological time, since the supercontinent Pangea was in existence. Our approach involves linking climate-sensitive sedimentary deposits such as

Seismology

The inherited structures within the Australian lithosphere define the tectonic evolution along the Banda arc

Integration of passive seismic images, geochemistry, and reconstruction of uplift from river profiles provide new findings on arc-continent collisional processes

Geophysics

Seismological Models, mineral physics and spin transitions in the lower mantle

The dominant variation of the physical properties of the Earth is with depth, though complex 3-D structures are present in the top 1000 km and near the core-mantle boundary.

Geodynamics

The Earth's troubled childhood

Continents host the oldest building blocks of the Earth's surface and keep a record of the processes that shaped it. A careful reading and high-performance computational modelling of the early, hotter Earth reveal a coming of age story.

Seismology

Imaging the full lithosphere with earthquake sources

When the seismic waves from a distant earthquake arrive in the vicinity of a seismic recording station they interact with the local structure and produce a variety of minor contributions accompanying the main arrival of a seismic phase.

Seismology

Probing the Australian-Pacific Plate Boundary (Pt 8: Sailing Home)

Unlike Sirens, who drew sailors to the rocks by their enchanted singing, causing their ships to sink, Nereids – the daughters of Doris and Nereus, the old man of the sea

Geophysics

Probing the Australian-Pacific Plate Boundary (Pt 7: The hunt for MRO21)

When you are pressed for time, the only thing you hope for is for things to go as smoothly as possible so that you can move on.

Geophysics

Shallow earthquakes in Australia

The Earth’s crust is made up of tectonic plates that are constantly in motion. Large, destructive earthquakes occur when accumulated energy at plate boundaries - where two plates are pushing against each other - is suddenly released.

Geodynamics

How is 'social distancing' maintained between strike-slip faults?

Haibin Yang, Louis Moresi and Mark Quigley provide a scaling relationship for the fault spacing in continental strike-slip shear zones.

Seismology

Probing the Australian-Pacific Plate Boundary (Pt 6: A race against time in sub-Antarctic waters)

... probably the most challenging feature in the global ocean on which to deploy ocean bottom seismometers, which need to land onto a relatively flat surface ...

Geophysics

Tweed Valley a ‘natural laboratory’ to model impacts of climate change and test carbon sequestration theory

Kyle Manley, Tristan Salles Dietmar Müller Since roughly 1880 the Earth has warmed by 1 deg C, many times faster than any warming episode in the past 65 million years

Geophysics

Probing the Australian-Pacific Plate Boundary (Pt 5: Underwater array observatory at the Macquarie Ridge)

Three and a half days after our departure from Hobart, we arrived in just northeast of the Macquarie island and instantly proceeded with swathing – mapping the ocean floor in the north-eastern quadrant, in lines parallel to the Macquarie ridge.

Geodynamics

On the destructive tendencies of cratons

Katie Cooper, Rebecca Farrington and Meghan Miller explain how cratonic lithosphere can be sculpted by flow from a passing subducting slab.

Seismology

Probing the Australian-Pacific Plate Boundary (Pt 4: What lies beneath ?)

A violent earthquake roared and rumbled through the underworld of a distant corner of the planet covered by the restless ocean, far enough from any soul to be felt or heard.

Opinion

Probing the Australian-Pacific Plate Boundary (Pt 3 — A voyage to the furious fifties)

“Below 40 degrees south there is no law, and below 50 degrees south there is no God."

Seismology

Probing the Australian-Pacific Plate Boundary (Pt 2 — On the Deck)

We (the team of 9 scientists and technicians from the Australian National University’s Research School of Earth Sciences) are out of strict 2-week quarantine and ready for a pre-voyage

Tectonics

How Earth's continents became twisted and contorted over millions of years

Figure: Photographed on Kangaroo Island, this rock – called a ‘zebra schist’ – deformed from flat-lying marine sediments through being stressed by a continental collision over 500 million years ago. Dietmar Muller

Geophysics

Rocky icebergs and deep anchors – new research on how planetary forces shape the Earth’s surface

A recent article in The Conversation by Simon Lamb from Victoria University of Wellington "uncovers the fundamental forces that control the Earth’s surface". They use Crust 1.0, ETOPO1, and the McKenzie and Priestley lithosphere model to compute their "Whole Layer Isostasy" model.

Geodynamics

Advanced geodynamic models of giant earthquakes

Though giant earthquakes are disastrous, they provide essential information to investigate earthquake physics. Thyagarajulu Gollapalli, a PhD student jointly from Monash University and the Indian Institute of Technology, Bombay, discusses our present understanding of such big earthquakes.