In only a couple of Orthodox Churches do we see totally different ritual traditions being celebrated within one autonomous church. And off the top of my head, an example of the same in the West is the Ge'ez Rite Catholic Church in DC under the jurisdiction of the Archdiocese of Washington, not the Ethiopian Catholic Church. Mixing liturgical rite and ecclesiastical jurisdiction is not the ideal, but it's tolerated under special circumstances.
Actually, we don't see totally different ritual traditions celebrated
within a different Church
sui iuris - not in that example at least. Kidane Meheret - the Ethiopian parish in DC is
juris alienos (subject to the law of another), a condition that has application only to canonical jurisdiction, not liturgical praxis. And such occurs whenever pastoral entities exist outside the historical bounds of their primatial hierarchs, unless the Church has a canonical jurisdiction in that area of the diaspora. (As regards liturgical praxis and spirituality, the 'stand-alone' parish in the diaspora remains subject to its primatial hierarch, assuming there is one - otherwise to the Congregation).
If an Ethiopian Orthodox wanted to convert to Catholicism while in America, then he would most likely be ascribed to the Latin Rite because there is no local Ethiopian Catholic eparchy with proper jurisdiction here. There's no provision that I know of that would ascribe the convert to another Eastern Catholic church that shares a closer liturgical relationship, such as the Coptic Catholic Church.
In any such instance, the Ethiopian Orthodox ought to be ascribed to the Ethiopian Catholic Church, unless he chose to be ascribed to another Church
sui iuris. (Frankly, the Ethiopian/Eritrean presence in NA is significantly larger than that of their Coptic Catholic brethren - a consequence of the unrest and economic hardships that have plagued their countries.)
Both the Codes place obligations on hierarchs who have within their jurisdiction faithful of another Church
sui iurisCanon 383 �1 In exercising his pastoral office, the diocesan Bishop is to be solicitous for all Christ's faithful entrusted to his care, whatever their age, condition or nationality, whether they live in the territory or are visiting there. He is to show an apostolic spirit also to those who, because of their condition of life, are not sufficiently able to benefit from ordinary pastoral care, and to those who have lapsed from religious practice.
�2 If he has faithful of a different rite in his diocese, he is to provide for their spiritual needs either by means of priests or parishes of the same rite, or by an episcopal Vicar.
Canon 193
1. The eparchial bishop to whom the care of Christian faithful of another Church sui iuris are committed is bound by the serious obligation of providing all the things in order that these Christian faithful retain the rite of their own Church, cultivate and observe it as much as they can; he should foster relations with the higher authority of that Church.
2. The eparchial bishop is to provide for the spiritual needs of those Christian faithful, if it is possible, through presbyters or pastors of the same Church sui iuris as the Christian faithful or even through a syncellus constituted for the care of these Christian faithful.
As a side note, the Eritreans within the Ethiopian Catholic Church have 1 parish in Canada and 5 missions there, each served once a month.
In the US, they share 1 parish and 2 active missions with the Ethiopians (the parish is principally Ethiopian but both missions are significantly more Eritrean than Ethiopian in membership). The Eritreans also have about 18 other mission communities, of which about a third are regularly served.
The Ethiopians have 2 missions which are not shared, but both are served only irregularly.
These are links to the
Ethiopian and
Eritrean parishes and missions in North America. Data is complete as to US and Canada (or as complete as can be, given that there is no other centralized listing for either group of which I'm aware).
To return for a moment to the comment about "totally different ritual traditions being celebrated
within" a different Church
sui iuris, I can think of only a single true instance of this:
The Metropolitan Arch-Eparchy of Kottayam of the Knanaites, a metropolia (without suffragn jurisdictions) within the Syro-Malabar Church
sui iuris has within it an Episcopal Vicariate for Malankara Knanaites. The fifteen parishes of the Vicariate canonically serve the Knanaite Usage of the Malankara Rescension of the Antiochene Rite (although the Metropolia is of the Chaldean Rite).
The other theoretical instance would be the historical ascription of the three Italo-Grieco-Albanian jurisdictions in Italy to the Western Patriarchate - for what that thought is worth.
The other instances which come to mind are:
- the Melkite involvement with several Russian parishes in the US and Australia;
- the Romanian involvement with another Russian parish in the US;
- the Melkite involvement with Italo-Greeks in Australia;
- the Ruthenian pastoral responsibility for Croats, Hungarians, and Slovaks in the US;
- the Ruthenian erection of an Italo-Greek parish in the US;
- the Ukrainian pastoral responsibility for Hungarians in Canada
(and I think I missed one, but the circumstances are identical in any instance)
These indeed represent "cross-overs" but don't meet the standard of "totally different ritual traditions" - given that all the Churches involved serve according to the Byzantine Rite. The instances of those
formally committed to the pastoral care of the Ruthenians and Ukrainians could, however, be cited to "ascribe (a) 'convert' (from - for instance - Hungarian Orthodoxy) to (an) Eastern Catholic church that shares a closer liturgical relationship" with his Church of origin - which has no formal canonical presence in this country.
Many years,
Neil