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IAGA Division 6 EMIW 2026

The Division 6 of IAGA organises a biennial workshop on Electromagnetic Induction. The 27th workshop is in 2026 and the call for proposals is out!

The proposal could be from a single country or be a joint venture of multiple countries. A 15 min oral presentation will take place in the 2022 Division Business Meeting. They should include the location, dates and cost of the workshop.

For more information, check the website of EMIW here

If you are interested in following this year's EMIW workshop, register here. The workshop would be in Turkey from 11th to 17th September 2022.

Q&A with IAGA!

All your questions about how IAGA works answered in this blog!

Where does IAGA get its funding from?

IAGA is a non-governmental body that is part of the International Union of Geodesy and Geophysics (IUGG). The IUGG has 58 regular and 15 associate member countries that pay subscriptions to it. This fee is used to fund the 8 organisations of IUGG, IAGA being one of them. Click here to know the process if your country would like to join IUGG.

How does IAGA appoint representatives?

On behalf of the Member Countries, IAGA is administered by an Executive Body that is elected by a Nominating Committee, following the by-laws mentioned here. Each country has a National Correspondent nominated by the national bodies. The Chief Delegates may vote on all matters. Officers normally serve 4 years (some 8 years). They preside over one IAGA and one IUGG General Meeting.

Can an Early Career Researcher be part of IAGA?

Any researcher can be a part of IAGA. There are no membership fees or formality to participate in the activities of the organisations. IAGA welcomes scientists from all over the world to take part in the Associations' events as well as scientific information exchange.

Can an Early Career Researcher be a representative of any IAGA Committee?

There are Early Career Liaison Representatives for each Division as well as Commission. Most of the ECRs are elected for this position. However, there are no age limits determined for other positions, which makes it possible for ECRs to represent IAGA in them as well. They may also act as National Correspondents of their country. To know more, they can contact the present Correspondents. The list can be found on this website under the 'Administration' tab.

Who do I contact if I have something (good/bad) to say/ask about the workings in my country?

You can contact your National Correspondents for any issue in your country. You may also contact the Executive Body for any details you might need or questions you might have. You can contact the Division members specifically if your query is related to it. You can find the contact information of all IAGA position holders here.

What a PhD on Core-Mantle Interaction looks like

I’m interested in how we can separate regions of the Earth’s main magnetic field into local regions to better understand how the mantle and core interact. It is important to remember that the main field is the most dominant contribution (>90%) to the Earth's magnetic field at the Earth's surface and changes over time due to the movement of conductive liquid in the outer core. This liquid is mostly composed of iron and is swirling in a complex current system due to the release of heat from the centre of the Earth, the turning motion of the planet, and the magnetic field perturbing the conductive liquid. Core flow and magnetic field models at the CMB tend to be described by spherical harmonics, which are not suitable for separation into individual regions due to large leakage being generated during the separation (Backus, 1968; Wieczorek and Simons, 2005). Spherical Slepian functions can spatially and spectrally separate bandlimited potential fields by transforming the spherical harmonic coefficients into the Slepian basis and sorting the functions by contribution to the patch (Simons and Plattner, 2015). 

We wished to make geophysical interpretations of the impact of the Large Low Velocity Provinces (LLVPs) on the core surface flow over time. LLVPs are two antipodal regions of anomalously low seismic velocity cover ~25% of the CMB surface (Koelemeijer, 2021). Long-lived features in the Earth’s magnetic field have been speculated to be linked to the LLVP structures as evidence for top-down control on the geodynamo (Tarduno et al., 2015). Whether these features apply a thermal forcing, a chemical exchange, dynamic topography or other effect to the core remains to be explored (McNamara, 2019; Zhao et al., 2015; Rhodri Davies et al., 2012).
The decomposition of SV at the Earth’s surface achieved from 5 biannual snapshots from May 2008 to May 2016 using 69 altitude-cognizant Slepian eigenfunctions to describe the Inside LLVPs. The blue circles in the global spherical harmonic plot show the data variability over the time period due to the satellite coverage.
In my PhD, we successfully incorporated spherical Slepian functions into regional SV inversions from satellite data for 2006–2021 and separated 150 years of COV-OBS.x2 SV model coefficients to investigate how LLVPs may be affecting core surface flow over time (Hammer et al., 2021; Huder et al, 2020). We identify that the energy within the region is incrementally changing over time. The spectral energy within the LLVPs at the Earth’s surface are changing over time and there is good correlation between periods of known acceleration change (from Mandea et al., 2010; and Duan and Huang, 2020) and inflection points in the spectra at l = 2 and l = 4 which reflect changes in signal due to antipodal structures. Inversions of satellite energy within the LLVPs have been relatively constant over the last 20 years and is roughly proportional to the surface area of the LLVPs but the longer time series shows a reduction in spectral energy within the LLVPs over time which is slowing over time. This work requires further investigations about the best applications of spherical Slepian functions, the cause of this SV change and extending the time period (e.g. using GGF100k, Panovska et al., 2019).

Hannah Rogers has just submitted her PhD thesis at the University of Edinburgh and is a member of the IAGA Social Media team. Her specialism is in investigating regional magnetic fields of Earth at the surface and the core-mantle boundary using mathematical methodologies. You can follow her on Twitter at @Hannah_Rogers94.